Science.gov

Sample records for air gun noise

  1. Impact of air gun noise on the behaviour of marine fish and squid.

    PubMed

    Fewtrell, J L; McCauley, R D

    2012-05-01

    In this study various species of captive marine fish and one species of squid were exposed to the noise from a single air gun. Six trials were conducted off the coast of Western Australia with each trial using a different noise exposure regime. Noise levels received by the animals ranged between 120 and 184 dB re 1 μPa(2).s (SEL). Behavioural observations of the fish and squid were made before, during and after air gun noise exposure. Results indicate that as air gun noise levels increase, fish respond by moving to the bottom of the water column and swimming faster in more tightly cohesive groups. Significant increases in alarm responses were observed in fish and squid to air gun noise exceeding 147-151 dB re 1 μPa SEL. An increase in the occurrence of alarm responses was also observed as noise level increased. PMID:22385754

  2. Water gun vs air gun: A comparison

    USGS Publications Warehouse

    Hutchinson, D.R.; Detrick, R. S.

    1984-01-01

    The water gun is a relatively new marine seismic sound source that produces an acoustic signal by an implosive rather than explosive mechanism. A comparison of the source characteristics of two different-sized water guns with those of conventional air guns shows the the water gun signature is cleaner and much shorter than that of a comparable-sized air gun: about 60-100 milliseconds (ms) for an 80-in3. (1.31-liter (I)) water gun compared with several hundred ms for an 80-in3. (1.31-1) air gun. The source spectra of water guns are richer in high frequencies (>200 Hz) than are those of air guns, but they also have less energy than those of air guns at low frequencies. A comparison between water gun and air gun reflection profiles in both shallow (Long Island Sound)-and deep (western Bermuda Rise)-water settings suggests that the water gun offers a good compromise between very high resolution, limited penetration systems (e.g. 3.5-kHz profilers and sparkers) and the large volume air guns and tuned air gun arrays generally used where significant penetration is required. ?? 1984 D. Reidel Publishing Company.

  3. Air gun test evaluation

    SciTech Connect

    Carleton, J.J. II; Fox, L.; Rudy, C.R.

    1992-01-15

    A mechanical shock testing apparatus is used for testing the response of components subject to large accelerations in hostile environments. The test acceleration is provided by the impact of a bullet against a plate on which the component to be tested is mounted. This report describes a series of experiments that were performed to determine the dependence of the air gun test apparatus performance on incremental changes in the hardware configurations, changes in the pressure used to drive the bullet, and different accelerometers. The effect of variation of these experimental factors on the measured acceleration was determined using a Taguchi screening experimental design. Experimental settings were determined that can be used to operate the tester with a measured output within acceleration specifications.

  4. Controlled-Temperature Hot-Air Gun

    NASA Technical Reports Server (NTRS)

    Munoz, M. C.

    1986-01-01

    Materials that find applications in wind tunnels first tested in laboratory. Hot-Air Gun differs from commercial units in that flow rate and temperature monitored and controlled. With typical compressed-airsupply pressure of 25 to 38 psi (170 to 260 kPa), flow rate and maximum temperature are 34 stdft3/min (0.96 stdm3/min) and 1,090 degrees F (590 degrees C), respectively. Resembling elaborate but carefully regulated hot-air gun, setup used to apply blasts of air temperatures above 1,500 degrees F (815 degrees C) to test specimens.

  5. Nozzle Extension for Safety Air Gun

    NASA Technical Reports Server (NTRS)

    Zumbrun, H. N.; Croom, Delwin R., Jr.

    1986-01-01

    New nozzle-extension design overcomes problems and incorporates original commercial nozzle, retaining intrinsic safety features. Components include extension tube, length of which made to suit application; adaptor fitting, and nozzle adaptor repinned to maintain original safety features. Design moves conical airstream to end of extension to blow machine chips away from operator. Nozzle-extension modification allows safe and efficient operation of machine tools while maintaining integrity of orginial safety-air-gun design.

  6. Air pollution: a smoking gun for cancer

    PubMed Central

    Zhang, Wei; Qian, Chao-Nan; Zeng, Yi-Xin

    2014-01-01

    Once considered a taboo topic or stigma, cancer is the number one public health enemy in the world. Once a product of an almost untouchable industry, tobacco is indisputably recognized as a major cause of cancer and a target for anticancer efforts. With the emergence of new economic powers in the world, especially in highly populated countries such as China, air pollution has rapidly emerged as a smoking gun for cancer and has become a hot topic for public health debate because of the complex political, economic, scientific, and technologic issues surrounding the air pollution problem. This editorial and the referred articles published in this special issue of the Chinese Journal of Cancer discuss these fundamental questions. Does air pollution cause a wide spectrum of cancers? Should air pollution be considered a necessary evil accompanying economic transformation in developing countries? Is an explosion of cancer incidence coming to China and how soon will it arrive? What must be done to prevent this possible human catastrophe? Finally, the approaches for air pollution control are also discussed. PMID:24636233

  7. Development of a Model to Assess Masking Potential for Marine Mammals by the Use of Air Guns in Antarctic Waters.

    PubMed

    Wittekind, Dietrich; Tougaard, Jakob; Stilz, Peter; Dähne, Michael; Clark, Christopher W; Lucke, Klaus; von Benda-Beckmann, Sander; Ainslie, Michael A; Siebert, Ursula

    2016-01-01

    We estimated the long-range effects of air gun array noise on marine mammal communication ranges in the Southern Ocean. Air gun impulses are subject to significant distortion during propagation, potentially resulting in a quasi-continuous sound. Propagation modeling to estimate the received waveform was conducted. A leaky integrator was used as a hearing model to assess communication masking in three species due to intermittent/continuous air gun sounds. Air gun noise is most probably changing from impulse to continuous noise between 1,000 and 2,000 km from the source, leading to a reduced communication range for, e.g., blue and fin whales up to 2,000 km from the source. PMID:26611093

  8. The Internal Ballistics of an Air Gun

    NASA Astrophysics Data System (ADS)

    Denny, Mark

    2011-02-01

    The internal ballistics of a firearm or artillery piece considers the pellet, bullet, or shell motion while it is still inside the barrel. In general, deriving the muzzle speed of a gunpowder firearm from first principles is difficult because powder combustion is fast and it very rapidly raises the temperature of gas (generated by gunpowder deflagration, or burning), which greatly complicates the analysis. A simple case is provided by air guns, for which we can make reasonable approximations that permit a derivation of muzzle speed. It is perhaps surprising that muzzle speed depends upon barrel length (artillerymen debated this dependence for centuries, until it was established experimentally and, later, theoretically ). Here we see that a simple physical analysis, accessible to high school or freshmen undergraduate physics students, not only derives realistic muzzle speed but also shows how it depends upon barrel length.

  9. Identification of Noise Sources and Design of Noise Reduction Measures for a Pneumatic Nail Gun

    PubMed Central

    Jayakumar, Vignesh; Zechmann, Edward

    2015-01-01

    An experimental-analytical procedure was implemented to reduce the operating noise level of a nail gun, a commonly found power tool in a construction site. The procedure is comprised of preliminary measurements, identification and ranking of major noise sources and application of noise controls. Preliminary measurements show that the impact noise transmitted through the structure and the exhaust related noise were found to be the first and second major contributors. Applying a noise absorbing foam on the outside of the nail gun body was found to be an effective noise reduction technique. One and two-volume small mufflers were designed and applied to the exhaust side of the nail gun which reduced not only the exhaust noise but also the impact noise. It was shown that the overall noise level could be reduced by as much as 3.5 dB, suggesting that significant noise reduction is possible in construction power tools without any significant increase of the cost. PMID:26366038

  10. Air gun pellet: cardiac penetration and peripheral embolization.

    PubMed

    Işık, Onur; Engin, Çağatay; Daylan, Ahmet; Şahutoğlu, Cengiz

    2016-05-01

    Use of high-velocity air guns can to lead to serious injuries. Management options of cardiac pellet gun injuries are based on patient stability, and course and location of the pellet. Presently reported is the case of a boy who was shot with an air gun pellet. Following right ventricular entry, the pellet lodged in the left atrium and embolized to the right iliac and femoral artery. Following pellet localization, right ventricular injury was repaired, and the pellet was removed successfully. PMID:27598599

  11. Noise Emission from Laboratory Air Blowers

    ERIC Educational Resources Information Center

    Rossing, Thomas D.; Windham, Betty

    1978-01-01

    Product noise ratings for a number of laboratory air blowers are reported and several recommendations for reducing laboratory noise from air blowers are given. Relevant noise ratings and methods for measuring noise emission of appliances are discussed. (BB)

  12. Air gun--a deadly toy?: A case report.

    PubMed

    Kuligod, F S; Jirli, Prasanna S; Kumar, Pradeep

    2006-04-01

    Air guns (air rifles) are used throughout the world as instruments of amusement such as toys in funfairs, for bird hunting and firearms training. In India and in many other countries, this instrument neither comes under the purview of the Arms Act, nor is there is any restriction on the user's age. This enables a person to gain access to this instrument quite easily. Sometimes serious and fatal injuries result when it is used by an ignorant person or by a criminal. There are reports which suggest that these 'toys' can cause painful injuries but only a few cases of death have been reported. There is no literature about the features of injuries that help to establish the range of fire by an air gun. Here we report a case where a boy was accidentally shot to death while watching bird shooting. We attempt to correlate the injury with the range of fire. PMID:16683474

  13. Serious air gun injuries in children: update of injury statistics and presentation of five cases.

    PubMed

    Myre, L E; Black, R E

    1987-09-01

    There were over 70,000 injuries to children caused by air guns reported from 1981 to 1984. The majority of these injuries were minor; however, serious injury resulted in eight deaths. Reported injuries include corneal perforation, liver laceration, stomach and intestinal perforation, intracranial bleeding, cardiac perforation, and hemopneumothorax. Primary care physicians must be aware of the potentially serious or lethal nature of air gun injury and educate their patients accordingly. Legislation is also needed to restrict the sale of these guns, or increase the safety of air gun use. We report five cases of potentially life-threatening injury caused by air guns, three of which required emergency laparotomy. PMID:3313302

  14. Air transportation noise technology overview

    NASA Technical Reports Server (NTRS)

    Maggin, B.; Chestnutt, D.

    1973-01-01

    The NASA and DOT technology program planning for quieter air transportation systems is reviewed. To put this planning in context, the nature of the noise problem and the projected nature of the air transportation fleet are identified. The technology program planning reviewed here is discussed in relation to the following areas of activity: systems analysis, community acceptance, basic research and technology, and the various classes of civil aircraft, i.e. existing and advanced transports, powered-lift transports, and general aviation.

  15. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase

    SciTech Connect

    Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui; Zhang, Jue Fang, Jing

    2015-10-15

    A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

  16. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase

    NASA Astrophysics Data System (ADS)

    Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui; Zhang, Jue; Fang, Jing

    2015-10-01

    A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

  17. Effects of Seismic Air Guns on Pallid Sturgeon and Paddlefish.

    PubMed

    Popper, Arthur N; Carlson, Thomas J; Gross, Jackson A; Hawkins, Anthony D; Zeddies, David; Powell, Lynwood; Young, John

    2016-01-01

    Pallid sturgeon and paddlefish were placed at different distances from a seismic air gun array to determine the potential effects on mortality and nonauditory body tissues from the sound from a single shot. Fish were held 7 days postexposure and then necropsied. No fish died immediately after sound exposure or over the postexposure period. Statistical analysis of injuries showed no differences between the experimental and control animals in either type or severity of injuries. There was also no difference in injuries between fish exposed closest to the source compared with those exposed furthest from the source. PMID:26611044

  18. Air gun injury with deadly aftermath--case report.

    PubMed

    Stankov, Aleksandar; Jakovski, Zlatko; Pavlovski, Goran; Muric, Nedzat; Dwork, Andrew J; Cakar, Zdravko

    2013-01-01

    In Republic of Macedonia the use of air guns is quite widespread. They are used mainly for target practice. They are regulated by the Law of Arms, where they are defined as pneumatic weapons. There is no legal limit on type or quantity of ammunition that one may possess. Our Institute performs at least 90% of the forensic autopsies in Macedonia. In this report we describe the only fatality by pneumatic weapon to come to our attention over the past 10 years. A 6-year-old girl was accidentally wounded by her brother when he and his father were trying a new air gun, a 4.5mm single shot, break barrel, spring piston air rifle manufactured in China under the brand "Westlake". She died within minutes. Autopsy showed cardiac tamponade due to penetration of the aorta. A 0.5g metal projectile, 4.5mm in diameter, with a pointed, conical shape, was recovered from the pericardial sac. PMID:23017978

  19. Air gun wounding and current UK laws controlling air weapons.

    PubMed

    Bruce-Chwatt, Robert Michael

    2010-04-01

    Air weapons whether rifles or pistols are, potentially, lethal weapons. The UK legislation is complex and yet little known to the public. Hunting with air weapons and the laws controlling those animals that are permitted to be shot with air weapons is even more labyrinthine due to the legal power limitations on the possession of air weapons. Still relatively freely available by mail order or on the Internet, an increasing number of deaths have been reported from the misuse of air weapons or accidental discharges. Ammunition for air weapons has become increasingly sophisticated, effective and therefore increasingly dangerous if misused, though freely available being a mere projectile without a concomitant cartridge containing a propellant and an initiator. PMID:20211450

  20. Phase noise reduction and photoelectron acceleration in a high-Q RF gun

    SciTech Connect

    Landahl, E.C.; Hartemann, F.V.; Baldis, H.A. |; Le Sage, G.P.; White, W.E.; Bennett, C.V.; Heritage, J.P.; Luhmann, N.C. Jr.; Ho, C.H.

    1998-06-01

    The phase noise and jitter characteristics of the laser and RF systems of a high-gradient X-band photoinjector have been measured experimentally. The laser oscillator is a self-mode-locked titanium: sapphire system operating at the 108th subharmonic of the RF gun. The X-band signal is produced from the laser by a phase-locked dielectric resonance oscillator and amplified by a pulsed TWT and klystron. A comparison between the klystron and TWT amplifier phase noise and the fields excited in the RF gun demonstrates the filtering effect of the high-Q structure, thus indicating that the RF gun can be used as a master oscillator and could be energized by either an RF oscillator, such as a magnetron, or a compact source, such as a cross-field amplifier. In particular, the RF gun can play the role of a pulsed RF clock to synchronize the photocathode laser system; direct drive of a synchronously mode-locked AlGaAs quantum well laser has been achieved using the X-band gun RF fields. This novel, gigahertz repetition rate, laser system is being developed to replace the more conventional femtosecond Ti:Al{sub 2}O{sub 3} system. Some advantages include pumping this laser with a stabilized current source instead of a costly, low-efficiency pump laser. Finally, dark current measurements and initial photoelectron measurements are reported.

  1. Air-moving device noise: An overview

    NASA Astrophysics Data System (ADS)

    Maling, George C., Jr.

    This paper presents a review of published information on the noise emission of small blowers and fans. The design is given for a noise meter for air-movement devices. The summary of research on noise sources and noise reduction includes information on axial-flow fans and centrifugal blowers. Sound reduction methods discussed include the introduction of obstructions and dampening plates and grilles. References are given for information on environmetal effects of fan noise. Design criteria and scaling laws are presented for minimal noise production. The paper identifies issues where further research is needed.

  2. Influence of pellet seating on the external ballistic parameters of spring-piston air guns.

    PubMed

    Werner, Ronald; Schultz, Benno; Frank, Matthias

    2016-09-01

    In firearm examiners' and forensic specialists' casework as well as in air gun proof testing, reliable measurement of the weapon's muzzle velocity is indispensable. While there are standardized and generally accepted procedures for testing the performance of air guns, the method of seating the diabolo pellets deeper into the breech of break barrel spring-piston air guns has not found its way into standardized test procedures. The influence of pellet seating on the external ballistic parameters was investigated using ten different break barrel spring-piston air guns. Test shots were performed with the diabolo pellets seated 2 mm deeper into the breech using a pellet seater. The results were then compared to reference shots with conventionally loaded diabolo pellets. Projectile velocity was measured with a high-precision redundant ballistic speed measurement system. In eight out of ten weapons, the muzzle energy increased significantly when the pellet seater was used. The average increase in kinetic energy was 31 % (range 9-96 %). To conclude, seating the pellet even slightly deeper into the breech of spring-piston air guns might significantly alter the muzzle energy. Therefore, it is strongly recommended that this effect is taken into account when accurate and reliable measurements of air gun muzzle velocity are necessary. PMID:27448569

  3. Country made scare gun vs. air gun--a comparative study of terminal ballistics using gelatine blocks.

    PubMed

    Hallikeri, Vinay R; Gouda, Hareesh S; Kadagoudar, Shivanand A

    2012-01-10

    Country made scare gun also called as bandook in the vernacular language designed with an intention of scaring away the menacing animals is not only unique and effective but also potentially lethal and has found wide spread usage in the rural parts of India. Here an attempt has been made to study the characteristic features such as physical dimensions, mechanism of action of this weapon and to compare its penetrating ability with that of air gun, whose potential lethality is a well-documented fact, using the ballistic gelatine blocks at various ranges. It is hoped that keeping the existence of such firearms in mind by the forensic experts might help to solve the unexplained and bizarre firearm injuries encountered in day to day practice. PMID:21839595

  4. Auditory Effects of Multiple Impulses from a Seismic Air Gun on Bottlenose Dolphins (Tursiops truncatus).

    PubMed

    Schlundt, Carolyn E; Finneran, James J; Branstetter, Brian K; Trickey, Jennifer S; Bowman, Victoria; Jenkins, Keith

    2016-01-01

    Auditory thresholds were measured in three bottlenose dolphins before and after exposure to ten impulses from a seismic air gun. Thresholds were measured using behavioral and electrophysiological methods to determine the amount of temporary threshold shift induced. The results suggest that the potential for seismic surveys using air guns to cause auditory effects on dolphins may be lower than previously predicted; however, two of the three dolphins exhibited "anticipatory" behavioral changes at the highest exposure condition that suggested they were attempting to mitigate the effects of the exposures. PMID:26611059

  5. Settlement Reached in Air Gun Use in Ocean-based Seismic Research

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    The U.S. National Science Foundation and the Center for Biological Diversity have settled a lawsuit brought against NSF that had threatened to scuttle the use of air gun arrays for use in NSF-sponsored seismic and geological studies at sea. The parties agreed to a 14 April dismissal of the suit. The CBD, an environmental organization based in Idyllwild, California, brought the suit in the U.S. District Court in San Francisco out of concern that the use of the air gun arrays may harm some marine mammals. CBD also claimed that NSF was not in compliance with several U.S. federal environmental regulations.

  6. Penetrated sigmoid colon by air gun pellet could be life threatening: A case report

    PubMed Central

    Krasniqi, Avdyl S.; Hamza, Astrit R.; Zejnullahu, Valon A.; Sada, Fatos E.; Bicaj, Besnik X.

    2014-01-01

    INTRODUCTION Air and paintball guns have been in existence for over 400 year. Although serious injury or death can result from the use of such guns, previous literature has not mentioned the issue of the penetration of the sigmoid colon by an air gun pellet. PRESENTATION OF CASE We report a rare case of a 44-year-old Caucasian woman referred to abdominal surgery after an accidental small wound had occurred in the lower left abdominal quadrant that was caused by an air gun pellet. The blood and biochemical analyses were normal but the CT scan revealed the presence of a foreign body – an air gun pellet in the left iliac region of the abdomen. Clinically, during the initial 24 h significant changes were not noticed. After 42 h, however, pain and local tenderness in the lower left abdominal quadrant was expressed. A laparotomy revealed a retained pellet in the wall of the sigmoid colon and a small leak with colonic content with consecutive local peritonitis also occurred. The foreign body was removed and the opening edges in the colon were excised and closed with the primary suture. DISCUSSION The hollow organs of the digestive tract, albeit very rarely penetrated by an air gun pellet, do not typically show all signs of an acute abdomen in the early posttraumatic phase. Such injuries can lead to a pronounced infection, which may cause septic shock if not appropriately treated. CONCLUSION For correct diagnosis, a careful approach and several daily clinical observations are required. PMID:25437671

  7. Noise Exposure on a Warship during Firing of a Heavy Machine Gun.

    PubMed

    Paddan, Gurmail S

    2015-11-01

    Sound pressure levels were measured on a military ship during firing of a Heavy Machine Gun (HMG). Measurements were made at three locations on the ship's bridge (the wheelhouse) and one location on the starboard bridge wing. The highest peak sound pressure levels measured on the bridge wing and on the bridge were 160.7 dB(C) (2170 Pa) and 122.7 dB(C) (27.3 Pa), respectively. The highest sound exposure levels measured on the bridge wing and on the bridge corresponding to one round being fired were 127.8 dB(A) and 88.9 dB(A), respectively. The ship's structure provided about 40 dB attenuation in the transmitted noise. The operator of the weapon would be required to wear some form of hearing protection. Based on the measured peak noise levels, there would be no requirement for bridge crew to wear any hearing protection during firing of a HMG. However, crew exposure to noise on the bridge is likely to exceed the upper exposure action value corresponding to 85 dB(A) after about 11 750 rounds. PMID:26240198

  8. A-weighting - It does not work indoors for helicopter or large gun noises; noises with low frequencies and large amplitudes

    NASA Astrophysics Data System (ADS)

    Schomer, Paul D.; Hoover, Brian D.

    Possible methods for correcting the measurements of high-amplitude 'impulsive' noise sources (such as noise from a helicopter or from a large gun) are discussed with special attention given to establishing a measure for these high-amplitude sounds. The concept of an impulsive sound is defined, and it is shown that the A-weighting schemes used widely to measure noise does not work for these impulsive noise sources. The reasons are as follows: (1) in the presence of a noticeable rattle generated by a helicopter sound, the A-weighted sound exposure level (ASEL) greatly underestimates the annoyance experienced indoors by up to 13 dB; (2) there is a structure/sound interaction whereby ASEL underestimates general helicopter noise annoyance indoors by 8 to 10 dB, and (3) detectability may well be a factor in the helicopter-noise annoyance.

  9. Use of a seismic air gun to reduce survival of nonnative lake trout embryos: A tool for conservation?

    USGS Publications Warehouse

    Cox, B.S.; Dux, A.M.; Quist, M.C.; Guy, C.S.

    2012-01-01

    The detrimental impacts of nonnative lake trout Salvelinus namaycush in the western USA have prompted natural resource management agencies in several states to implement lake trout suppression programs. Currently, these programs rely on mechanical removal methods (i.e., gill nets, trap nets, and angling) to capture subadult and adult lake trout. We conducted a study to explore the potential for using high-intensity sound from a relatively small (655.5 cm3 [40 in3]) seismic air gun to reduce survival of lake trout embryos. Lake trout embryos at multiple stages of development were exposed to a single discharge of the seismic air gun at two depths (5 and 15 m) and at two distances from the air gun (0.1 and 2.7 m). Control groups for each developmental stage, distance, and depth were treated identically except that the air gun was not discharged. Mortality in lake trout embryos treated at 0.1 m from the air gun was 100% at 74 daily temperature units in degrees Celsius (TU°C) at both depths. Median mortality in lake trout embryos treated at 0.1 m from the air gun at 207 TU°C (93%) and 267 °C (78%) appeared to be higher than that of controls (49% and 48%, respectively) at 15-m depth. Among the four lake trout developmental stages, exposure to the air gun at 0.1 m resulted in acute mortality up to 60% greater than that of controls. Mortality at a distance of 2.7 m did not appear to differ from that of controls at any developmental stage or at either depth. Our results indicate that seismic air guns have potential as an alternative tool for controlling nonnative lake trout, but further investigation is warranted.

  10. Extensive Air Showers: from the muonic smoking guns to the hadronic backbone

    NASA Astrophysics Data System (ADS)

    Cazon, L.

    2013-06-01

    Extensive Air Showers are complex macroscopic objects initiated by single ultra-high energy particles. They are the result of millions of high energy reactions in the atmosphere and can be described as the superposition of hadronic and electromagnetic cascades. The hadronic cascade is the air shower backbone, and it is mainly made of pions. Decays of neutral pions initiate electromagnetic cascades, while the decays of charged pions produce muons which leave the hadronic core and travel many kilometers almost unaffected. Muons are smoking guns of the hadronic cascade: the energy, transverse momentum, spatial distribution and depth of production are key to reconstruct the history of the air shower. In this work, we overview the phenomenology of muons on the air shower and its relation to the hadronic cascade. We briefly review the experimental efforts to analyze muons within air showers and discuss possible paths to use this information.

  11. First assessment of effects of air-gun seismic shooting on marine resources in the central Adriatic sea

    SciTech Connect

    La Bella, G.; Cannata, S.; Froglia, C.

    1996-11-01

    A series of investigations were carried out to test the effects of air-gun seismic shooting on main fishery resources of the Adriatic Sea during summer 1995. The energy source used for the trial was formed by one air-gun array made up by two sub-arrays consisting in 8 air-guns each developing a total volume of c.a. 2500 i{sup 3} at 2000 psi with an amplitude of 60 bar/m. The interval between two was of 25 s. The intensity was of 210 dB re 1 mPa-m/Hz. Acoustical and spectral analysis were performed simultaneously in the surveyed areas to correlate fishery and behavior observations with sound pattern of the energization. Main results were: (1) Analysis of trawl catch data evidenced no significant changes before and after the air-gun seismic profiling. (2) Echosurvey relative estimate of pelagic biomass, performed simultaneously to trawling operations, failed to evidence any significant change in the pelagic biomass subsequent to the seismic shooting. (3) Small differences were observed in the trammel net catch composition, but one single set of pre-post fishing operations could be done in the study period. (4) Similar density estimate were obtained from dredge surveys performed by an hydraulic dredger before and after air-gun seismic profiling over a clam bed in 14 in depth. (5) Video recording of captive fish, kept into cages moored on the sea bottom at 12 in depth, evidenced a Behavioral response to the approach of the sound source; but no lethal event was recorded on captive sea-bass immediately after the seismic shooting. (6) Biochemical and histological analysis were performed to verify if it is to be related to the captive condition or is somewhat consequent to the air-gun energization. These results confirm that no relevant effects are induced on fishery resources by seismic air-gun shooting.

  12. MODE IDENTIFICATION OF AN ARCH DAM BY A DYNAMIC AIR-GUN TEST.

    USGS Publications Warehouse

    Liu, Hsi-Ping; Fedock, Joseph J.; Fletcher, Jon B.

    1986-01-01

    Thirteen natural frequencies of a concrete arch dam (Monticello Dam near Sacramento, California) have been identified by using a dynamic testing method which employs an air gun firing in the reservoir as the excitation source. These vibrations modes are determined from the peak responses in the Fourier amplitude spectra of the free-vibration data recorded at three crest locations using three-component geophones. Comparisons of the first five natural frequencies with results obtained by forced vibration tests using rotating mass shakers show good agreement. The next eight higher-frequency modes, not previously identified, are determined from data of the present tests.

  13. The simulation of far-field wavelets using frequency-domain air-gun array near-field wavelets

    NASA Astrophysics Data System (ADS)

    Song, Jian-Guo; Deng, Yong; Tong, Xin-Xin

    2013-12-01

    Air-gun arrays are used in marine-seismic exploration. Far-field wavelets in subsurface media represent the stacking of single air-gun ideal wavelets. We derived single air-gun ideal wavelets using near-field wavelets recorded from near-field geophones and then synthesized them into far-field wavelets. This is critical for processing wavelets in marineseismic exploration. For this purpose, several algorithms are currently used to decompose and synthesize wavelets in the time domain. If the traveltime of single air-gun wavelets is not an integral multiple of the sampling interval, the complex and error-prone resampling of the seismic signals using the time-domain method is necessary. Based on the relation between the frequency-domain phase and the time-domain time delay, we propose a method that first transforms the real near-field wavelet to the frequency domain via Fourier transforms; then, it decomposes it and composes the wavelet spectrum in the frequency domain, and then back transforms it to the time domain. Thus, the resampling problem is avoided and single air-gun wavelets and far-field wavelets can be reliably derived. The effect of ghost reflections is also considered, while decomposing the wavelet and removing the ghost reflections. Modeling and real data processing were used to demonstrate the feasibility of the proposed method.

  14. A piloted simulation investigation of yaw dynamics requirements for turreted gun use in low-level helicopter air combat

    NASA Technical Reports Server (NTRS)

    Decker, William A.; Morris, Patrick M.; Williams, Jeffrey N.

    1988-01-01

    A piloted, fixed-base simulation study was conducted to investigate the handling qualities requirements for helicopter air-to-air combat using turreted guns in the near-terrain environment. The study used a version of the helicopter air combat system developed at NASA Ames Research Center for one-on-one air combat. The study focused on the potential trade-off between gun angular movement capability and required yaw axis response. Experimental variables included yaw axis response frequency and damping and the size of the gun-movement envelope. A helmet position and sighting system was used for pilot control of gun aim. Approximately 340 simulated air combat engagements were evaluated by pilots from the Army and industry. Results from the experiment indicate that a highly-damped, high frequency yaw response was desired for Level I handling qualities. Pilot preference for those characteristics became more pronounced as gun turret movement was restricted; however, a stable, slow-reacting platform could be used with a large turret envelope. Most pilots preferred to engage with the opponent near the own-ship centerline. Turret elevation restriction affected the engagement more than azimuth restrictions.

  15. Experimental effect of shots caused by projectiles fired from air guns with kinetic energy below 17 J.

    PubMed

    Smędra-Kaźmirska, Anna; Barzdo, Maciej; Kędzierski, Maciej; Antoszczyk, Łukasz; Szram, Stefan; Berent, Jarosław

    2013-09-01

    Pursuant to the Polish Weapons and Ammunitions Law (Legal Gazette No 53/1999 item 549 with subsequent amendments), air guns with kinetic energy of the fired projectiles below 17 J are not regarded as weapons. The aim of the study was to assess the potential effect of shots caused by projectiles of various mass and structure fired from air guns with kinetic energy below 17 J on human soft tissues. As a model of soft tissue, we used 20% gelatin blocks. After shooting, we measured the depth of gelatin block penetration by pellets fired from various distances and compared these results with autopsy findings. The results demonstrated that examined pneumatic guns may cause serious injuries, including damage to the pleura, pericardium, liver, spleen, kidneys, femoral artery, and thoracic and abdominal aorta. Experiment shown that gelatin blocks do not reflect fully the properties of the human body. PMID:23919403

  16. Quantitative measures of air-gun pulses recorded on sperm whales (Physeter macrocephalus) using acoustic tags during controlled exposure experiments.

    PubMed

    Madsen, P T; Johnson, M; Miller, P J O; Aguilar Soto, N; Lynch, J; Tyack, P

    2006-10-01

    The widespread use of powerful, low-frequency air-gun pulses for seismic seabed exploration has raised concern about their potential negative effects on marine wildlife. Here, we quantify the sound exposure levels recorded on acoustic tags attached to eight sperm whales at ranges between 1.4 and 12.6 km from controlled air-gun array sources operated in the Gulf of Mexico. Due to multipath propagation, the animals were exposed to multiple sound pulses during each firing of the array with received levels of analyzed pulses falling between 131-167 dB re. 1 microPa (pp) [111-147 dB re. 1 microPa (rms) and 100-135 dB re. 1 microPa2 s] after compensation for hearing sensitivity using the M-weighting. Received levels varied widely with range and depth of the exposed animal precluding reliable estimation of exposure zones based on simple geometric spreading laws. When whales were close to the surface, the first arrivals of air-gun pulses contained most energy between 0.3 and 3 kHz, a frequency range well beyond the normal frequencies of interest in seismic exploration. Therefore air-gun arrays can generate significant sound energy at frequencies many octaves higher than the frequencies of interest for seismic exploration, which increases concern of the potential impact on odontocetes with poor low frequency hearing. PMID:17069331

  17. Factor of safety method, application to air and noise pollution

    SciTech Connect

    Green, A.E.S.; Buckley, T.J.; Rio, D.E.; Makarewicz, R.; MacEachern, A.

    1980-01-01

    Technical report:Air quality indexes were used to calculate air and noise pollution factors of safety for 82 U.S. cities. Pollutants considered in the safety study are: total suspended particulates, sulfur dioxide, carbon monoxide, nitrogen dioxide, and ozone. Mathematical models that were used to calculate the factors of safety are presented. The utilization of air quality indexes for regional planning and decision-making is discussed. (5 graphs, 3 photos, 25 references, 6 tables)

  18. The inner ears of Northern Canadian freshwater fishes following exposure to seismic air gun sounds.

    PubMed

    Song, Jiakun; Mann, David A; Cott, Peter A; Hanna, Bruce W; Popper, Arthur N

    2008-08-01

    An earlier study examined the effects of exposure to seismic air guns on the hearing of three species of fish from the Mackenzie River Delta in Northern Canada [Popper et al. (2005). "Effects of exposure to seismic airgun use on hearing of three fish species," J. Acoust. Soc. Am. 117, 3958-3971]. The sound pressure levels to which the fishes were exposed were a mean received level of 205-209 dB re 1 microPa (peak) per shot and an approximate received mean SEL of 176-180 dB re 1 microPa(2) s per shot. In this report, the same animals were examined to determine whether there were effects on the sensory cells of the inner ear as a result of the seismic exposure. No damage was found to the ears of the fishes exposed to seismic sounds despite the fact that two of the species, adult northern pike and lake chub, had shown a temporary threshold shift in hearing studies. PMID:18681621

  19. The inner ears of Northern Canadian freshwater fishes following exposure to seismic air gun sounds

    PubMed Central

    Song, Jiakun; Mann, David A.; Cott, Peter A.; Hanna, Bruce W.; Popper, Arthur N.

    2008-01-01

    An earlier study examined the effects of exposure to seismic air guns on the hearing of three species of fish from the Mackenzie River Delta in Northern Canada [Popper et al. (2005). “Effects of exposure to seismic airgun use on hearing of three fish species,” J. Acoust. Soc. Am. 117, 3958–3971]. The sound pressure levels to which the fishes were exposed were a mean received level of 205–209 dB re 1 μPa (peak) per shot and an approximate received mean SEL of 176–180 dB re 1 μPa2 s per shot. In this report, the same animals were examined to determine whether there were effects on the sensory cells of the inner ear as a result of the seismic exposure. No damage was found to the ears of the fishes exposed to seismic sounds despite the fact that two of the species, adult northern pike and lake chub, had shown a temporary threshold shift in hearing studies. PMID:18681621

  20. Study of noise transmission from an air compressor

    NASA Astrophysics Data System (ADS)

    Nathak, Subhro; Puranik, Anand; Schut, Jeffrey; Wells, Lee; Rao, M. D.

    2005-09-01

    The paper discusses the reduction of noise from a Porter Cable 4-gal, 135-psi air compressor. The objectives were to identify the major sources of noise, implement possible noise control measures, and evaluate their effectiveness. Sound measurements were taken according to a procedure that was developed and based on the standards for power tools. Broadband analysis (1/12 octave band) was done to determine the main sources of noise. Ranking of noise sources was done accordingly. The major source of noise was determined to be the piston cylinder assembly and efforts were taken to reduce this main source of noise. The noise control treatments included manufacturing of new parts, use of gasket made of cork between the housing and the cylinder sleeve to isolate the vibrations, implementing a silencer at the exhaust side of the piston and finally, an enclosure encircling the piston/cylinder assembly. The sound-pressure level measurements of the prototype were compared to the baseline measurements to test the effectiveness of the treatments. The overall sound pressure level was reduced from 101.5 to 94.3 dB with the implementation of enclosure around the piston/cylinder assembly and the silencer at the exhaust side of the piston.

  1. Attenuating noise generated by variable-air-volume systems

    SciTech Connect

    Stokes, R.

    1985-03-01

    Sound generated by HVAC systems is receiving much attention because they are generally the principal contributors to room background sound levels that may become irritating and distracting noise if not controlled. This article discusses the creation of a quiet working environment through an analysis of the three traditional sound paths associated with air handling systems: radiated sound, inlet or return air sound and discharge sound. Recommended standards are given as well as a brief overview of materials used to fabricate HVAC system components.

  2. Low-noise flow valve for air ducts

    NASA Technical Reports Server (NTRS)

    Gallo, E. A.

    1970-01-01

    Valve assembly controls air flow from feeder into main duct, with minimum of turbulence, friction, pressure differential, and noise. Valve consists of damper, deflector, and spring. Streamlining of damper and deflector merges flow smoothly, while spring keeps damper and deflector in contact and eliminates valve chatter and damping vibrations.

  3. Homemade Firearm Suicide With Dumbbell Pipe Triggering by an Air-Compressed Gun: Case Report and Review of Literature.

    PubMed

    Le Garff, Erwan; Delannoy, Yann; Mesli, Vadim; Berthezene, Jean Marie; Morbidelli, Philippe; Hédouin, Valéry

    2015-12-01

    Firearm suicides are frequent and well described in the forensic literature, particularly in Europe and the United States. However, the use of homemade and improvised firearms is less well described. The present case reports a suicide with an original improvised gun created using an air-compressed pellet gun and a dumbbell pipe. The aims of this study were to describe the scene, the external examination of the corpse, the body scan, and the autopsy; to understand the mechanism of death; and to compare the results with a review of the forensic literature to highlight the epidemiology of homemade firearm use, the tools used for homemade and improvised firearms in suicides versus homicides, and the manners in which homemade firearms are used (homicide or suicide, particularly in complex suicide cases). PMID:26375571

  4. Noise Reduction Of Air Blower Casing Using Composites

    NASA Astrophysics Data System (ADS)

    Kolla*, S.; Kumar, Y. Anil; Rajesh, S.

    Sound subjectively, what is heard by the ear; objectively, is a mecha nical disturbance from equilibrium in an elastic medium. The noise produced by a rotating component has two main components, the broadband noise and the discrete frequency noise. The broadband noise from a rotor is due to random loading forces on the blades, which are induced by the absorption of atmospheric turbulence. The discrete frequency noise is due to periodic interaction of incoming air with the blades of the rotor. At present the centrifugal blowers, in Naval defense application which is made of steel is generating a noise of 86dB, which causes mental imbalance to the people working near the blower on ship. Therefore in Naval defense applications the reduction of sound level from a source is very important and critical task. Hence the objective of this paper is to reduce the noise level produced by the metal air blower. The noise radiated by the casing of a centrifugal blower can be effectively reduced by the use of (1) Composite Materials, (2) Visco-Elastic material treatment and (3) Stiffness addition. In this paper it is proposed to carry out a study to evaluate the effectiveness of composites in reducing noise levels of the casing. Composite materials are those containing more than one bonded material, each with different struc tural properties. The advantage of composite materials is the potential for a high ratio of stiffness to weight. In order to evaluate the effectiveness of composites over metals, modal analysis (Eigen value analysis) and Static analysis was performed on both composite and metal blowers using FEA package (ANSYS). Modal analysis is performed on both metals (Alluminium and Composite) blower casing to find out the first ten natural frequencies and static analysis is performed for a pressure of 1570 Pa. This paper also describes the experimental setup of the centrifugal blower, the values of the sound levels for both metal and FRP blowers are taken at a distance of

  5. Acoustic background noise variation in Air Force platforms and its effect on noise removal algorithms

    NASA Astrophysics Data System (ADS)

    Lafollette, Philip A.

    1991-06-01

    In this study of short-term noise variation in Air Force platforms, we followed two avenues of investigation. First, we applied quantitative measures of variation to individual noise recordings, and compared the results across various aircraft. Some measures used were simple descriptive statistics, but we also measured attenuation obtained by spectral restoration (spectral subtraction), applied to the noise signal alone. The noise attenuation obtained for real aircraft environments was in most cases about the same as predicted theoretically for white Gaussian noise, but in some instances was considerably higher, especially in the presence of propeller noise. Second, we applied the nonparametric Mann-Whitney statistic to test the stationarity of power spectrum estimates on time scales of 200 to 800 ms. There was little or no evidence of nonstationarity in large jet or turboprop aircraft. In fighter aircraft and helicopters, there was some evidence of nonstationarity confined to more or less narrow frequency ranges. The nonstationarity found did not appear to limit the performance of special restoration algorithms. The noise recordings used were taken from the RADC/EEV database of field recordings made in the E-3A, E-4B, EC-135, E-130, P-3C, F-15, F-16, F-4, A-10, HH-53 and Tornado aircraft.

  6. Far Noise Field of Air Jets and Jet Engines

    NASA Technical Reports Server (NTRS)

    Callaghan, Edmund E; Coles, Willard D

    1957-01-01

    An experimental investigation was conducted to study and compare the acoustic radiation of air jets and jet engines. A number of different nozzle-exit shapes were studied with air jets to determine the effect of exit shape on noise generation. Circular, square, rectangular, and elliptical convergent nozzles and convergent-divergent and plug nozzles were investigated. The spectral distributions of the sound power for the engine and the air jet were in good agreement for the case where the engine data were not greatly affected by reflection or jet interference effects. Such power spectra for a subsonic or slightly choked engine or air jet show that the peaks of the spectra occur at a Strouhal number of 0.3.

  7. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  8. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Portable air compressor noise emission standard. 204.52 Section 204.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors § 204.52 Portable air compressor...

  9. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  10. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  11. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  12. Gun Play

    ERIC Educational Resources Information Center

    Mechling, Jay

    2008-01-01

    Biology and the particular gun culture of the United States come together to explain the persistent and powerful attraction of American boys to both real guns and toy guns. The 1990s saw adults begin to conflate "the gun problem" with "the boy problem," sparking attempts (largely failed) to banish toy guns from homes and…

  13. Quantifying the uncertainty of geoacoustic parameter estimates for the New Jersey shelf by inverting air gun data.

    PubMed

    Jiang, Yong-Min; Chapman, N Ross; Badiey, Mohsen

    2007-04-01

    This paper describes geoacoustic inversion of low frequency air gun data acquired during an experiment on the New Jersey shelf. Hybrid optimization and Bayesian inversion techniques based on matched field processing were applied to multiple shots from three air gun data sets recorded by a vertical line array in a long-range shallow water geometry. For the Bayesian inversions, full data error covariance matrix was estimated from a set of consecutive shots that had high temporal coherence and small spatial variation in source position. The effect of different data error information on the geoacoustic parameter uncertainty estimates was investigated by using the full data error covariance matrix, a diagonalized version of the full error covariance, and a diagonal matrix with identical variances. The comparison demonstrated that inversion using the full data error information provided the most reliable parameter uncertainty estimates. The inversions were highly sensitive to the near sea floor geoacoustic parameters, including sediment attenuation, of a simple single-layer geoacoustic model. The estimated parameter values of the model were consistent with depth averaged values (over wavelength scales) of a high resolution geoacoustic model developed from extensive ground truth information. The interpretation of the frequency dependence of the estimated attenuation is also discussed. PMID:17471704

  14. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  15. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  16. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  17. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Portable air compressor noise emission standard. 204.52 Section 204.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors §...

  18. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  19. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  20. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  1. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  2. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Portable air compressor noise emission standard. 204.52 Section 204.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors §...

  3. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Portable air compressor noise emission standard. 204.52 Section 204.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors §...

  4. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  5. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Portable air compressor noise emission standard. 204.52 Section 204.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors §...

  6. Seismic air gun exposure during early-stage embryonic development does not negatively affect spiny lobster Jasus edwardsii larvae (Decapoda: Palinuridae).

    PubMed

    Day, Ryan D; McCauley, Robert D; Fitzgibbon, Quinn P; Semmens, Jayson M

    2016-01-01

    Marine seismic surveys are used to explore for sub-seafloor oil and gas deposits. These surveys are conducted using air guns, which release compressed air to create intense sound impulses, which are repeated around every 8-12 seconds and can travel large distances in the water column. Considering the ubiquitous worldwide distribution of seismic surveys, the potential impact of exposure on marine invertebrates is poorly understood. In this study, egg-bearing female spiny lobsters (Jasus edwardsii) were exposed to signals from three air gun configurations, all of which exceeded sound exposure levels (SEL) of 185 dB re 1 μPa(2) · s. Lobsters were maintained until their eggs hatched and the larvae were then counted for fecundity, assessed for abnormal morphology using measurements of larval length and width, tested for larval competency using an established activity test and measured for energy content. Overall there were no differences in the quantity or quality of hatched larvae, indicating that the condition and development of spiny lobster embryos were not adversely affected by air gun exposure. These results suggest that embryonic spiny lobster are resilient to air gun signals and highlight the caution necessary in extrapolating results from the laboratory to real world scenarios or across life history stages. PMID:26947006

  7. Seismic air gun exposure during early-stage embryonic development does not negatively affect spiny lobster Jasus edwardsii larvae (Decapoda:Palinuridae)

    PubMed Central

    Day, Ryan D.; McCauley, Robert D.; Fitzgibbon, Quinn P.; Semmens, Jayson M.

    2016-01-01

    Marine seismic surveys are used to explore for sub-seafloor oil and gas deposits. These surveys are conducted using air guns, which release compressed air to create intense sound impulses, which are repeated around every 8–12 seconds and can travel large distances in the water column. Considering the ubiquitous worldwide distribution of seismic surveys, the potential impact of exposure on marine invertebrates is poorly understood. In this study, egg-bearing female spiny lobsters (Jasus edwardsii) were exposed to signals from three air gun configurations, all of which exceeded sound exposure levels (SEL) of 185 dB re 1 μPa2·s. Lobsters were maintained until their eggs hatched and the larvae were then counted for fecundity, assessed for abnormal morphology using measurements of larval length and width, tested for larval competency using an established activity test and measured for energy content. Overall there were no differences in the quantity or quality of hatched larvae, indicating that the condition and development of spiny lobster embryos were not adversely affected by air gun exposure. These results suggest that embryonic spiny lobster are resilient to air gun signals and highlight the caution necessary in extrapolating results from the laboratory to real world scenarios or across life history stages. PMID:26947006

  8. Meeting 2006, outdoor noise directive (OND) noise levels for a diesel engine driven air compressor: A case study in noise reduction

    NASA Astrophysics Data System (ADS)

    Rowe, David F.

    2005-09-01

    In January 2006, the noise limits for many products in the European Union will drop by 2-3 dBA, as directed by 2000/14/EC ``Noise Emission in the Environment by Equipment Used Outdoors,'' commonly called the ``Outdoor Noise Directive,'' or ``OND.'' Air compressors are among the products addressed by this directive. At Ingersoll-Rand, significant effort has been directed at meeting the challenge of reducing noise on a variety of diesel engine driven air compressor platforms, ranging from 15 to 350 kW diesel engine power ratings. This paper presents a case study of the noise reduction on a 750 cfm (21 m3/min) air compressor operating at 300 psig (21 bar), to meet the 2006 OND noise limit of 100 LwA.

  9. Environment and air pollution like gun and bullet for low-income countries: war for better health and wealth.

    PubMed

    Zou, Xiang; Azam, Muhammad; Islam, Talat; Zaman, Khalid

    2016-02-01

    The objective of the study is to examine the impact of environmental indicators and air pollution on "health" and "wealth" for the low-income countries. The study used a number of promising variables including arable land, fossil fuel energy consumption, population density, and carbon dioxide emissions that simultaneously affect the health (i.e., health expenditures per capita) and wealth (i.e., GDP per capita) of the low-income countries. The general representation for low-income countries has shown by aggregate data that consist of 39 observations from the period of 1975-2013. The study decomposes the data set from different econometric tests for managing robust inferences. The study uses temporal forecasting for the health and wealth model by a vector error correction model (VECM) and an innovation accounting technique. The results show that environment and air pollution is the menace for low-income countries' health and wealth. Among environmental indicators, arable land has the largest variance to affect health and wealth for the next 10-year period, while air pollution exerts the least contribution to change health and wealth of low-income countries. These results indicate the prevalence of war situation, where environment and air pollution become visible like "gun" and "bullet" for low-income countries. There are required sound and effective macroeconomic policies to combat with the environmental evils that affect the health and wealth of the low-income countries. PMID:26493298

  10. The Hydraulic Mechanism in the Orbital Blowout Fracture Because of a High-Pressure Air Gun Injury.

    PubMed

    Kang, Seok Joo; Chung, Eui Han

    2015-10-01

    There are 2 predominant mechanisms that are used to explain the pathogenesis of orbital blowout fracture; these include hydraulic and buckling mechanisms. Still, however, its pathophysiology remains uncertain. To date, studies in this series have been conducted using dry skulls, cadavers, or animals. But few clinical studies have been conducted to examine whether the hydraulic mechanism is involved in the occurrence of pure orbital blowout fracture. The authors experienced a case of a 52-year-old man who had a pure medial blowout fracture after sustaining an eye injury because of a high-pressure air gun. Our case suggests that surgeons should be aware of the possibility that the hydraulic mechanism might be involved in the blowout fracture in patients presenting with complications, such as limitation of eye movement, diplopia, and enophthalmos. PMID:26468824

  11. Magnetic Ignition of Pulsed Gas Discharges in Air of Low Pressure in a Coaxial Plasma Gun

    NASA Technical Reports Server (NTRS)

    Thom, Karlheinz; Norwood, Joseph, Jr.

    1961-01-01

    The effect of an axial magnetic field on the breakdown voltage of a coaxial system of electrodes has been investigated by earlier workers. For low values of gas pressure times electrode spacing, the breakdown voltage is decreased by the application of the magnetic field. The electron cyclotron radius now assumes the role held by the mean free path in nonmagnetic discharges and the breakdown voltage becomes a function of the magnetic flux density. In this paper the dependence of the formative time lag as a function of the magnetic flux density is established and the feasibility of using a magnetic field for igniting high-voltage, high-current discharges is shown through theory and experiment. With a 36 microfarad capacitor bank charged to 48,000 volts, a peak current of 1.3 x 10( exp 6) amperes in a coaxial type of plasma gun was achieved with a current rise time of only 2 microseconds.

  12. Noise impacts from professional dog grooming forced-air dryers

    PubMed Central

    Scheifele, Peter M.; Johnson, Michael T.; Byrne, David C.; Clark, John G.; Vandlik, Ashley; Kretschmer, Laura W.; Sonstrom, Kristine E.

    2015-01-01

    This study was designed to measure the sound output of four commonly used brands of forced-air dryers used by dog groomers in the United States. Many dog groomers have questions about the effect of this exposure on their hearing, as well as on the hearing of the dogs that are being groomed. Readings taken from each dryer at 1 meter (the likely distance of the dryer from the groomer and the dog) showed average levels ranging from 105.5 to 108.3 dB SPL or 94.8 to 108.0 dBA. Using the 90 dBA criterion required by the US Occupational Safety and Health Administration, dog groomers/bathers are at risk if exposure to the lowest intensity dryer (94.8 dBA) exceeds 4 hours per day. If the more stringent 85 dBA criterion and 3 dB tradeoff is applied, less than one hour of exposure is permissible in an 8 hour day. Cautions are recommended for any persons exposed to noise from forced-air dryers. PMID:23117536

  13. Gas gun dynamics

    NASA Astrophysics Data System (ADS)

    Denny, Mark

    2013-09-01

    The mechanics and thermodynamics of one- and two-stage gas guns are developed. Very high projectile muzzle speed can be obtained by the two-stage version. The physics of simple gas guns, such as air rifles, is accessible to undergraduates and the same level of presentation is used here to understand more complex designs. Numerical solutions to the equations of motion are shown, along with insightful analytic approximations.

  14. Gun Safety

    MedlinePlus

    Many U.S. households have guns, but they can cause harm if not handled properly. Here are some things you can do to keep yourself and ... safe: Teach children that they shouldn't touch guns and that if they see a gun, to ...

  15. 3D Tomographic Imaging of the Crustal Velocity Structure beneath the Marmara Sea using Air-gun and Earthquake Data

    NASA Astrophysics Data System (ADS)

    Tarancioglu, Adil; Kocaoglu, Argun H.; Ozalaybey, Serdar

    2014-05-01

    The objective of this study is to investigate the local seismicity and obtain a detailed three-dimensional crustal velocity structure beneath the Marmara Sea in an area surrounding the North Anatolian Fault Zone (NAFZ) by tomographic inversion using both controlled-source (air-gun) and earthquake data. The tomographic inversion is carried out by using the local earthquake tomography code SIMUL2000. Two sets of seismological data, collected in 2006 (EOSMARMARA experiment) and 2001 (SEISMARMARA experiment), are re-processed and used in this study. A total of 441 high quality earthquakes and 452 air-gun shots recorded by a total of 53 Ocean Bottom Seismometers (OBS) are selected for the simultaneous inversion for velocity and hypocentral parameters. The OBS location and time-drift errors are identified from air-gun shot records by a grid search method and required corrections are made on the travel time data. The initial (reference) velocity model and earthquake locations required for the three dimensional tomographic inversion are derived from the one-dimensional velocity model obtained by using the VELEST algorithm in which a subset of earthquakes are selected such that phase readings were made by at least five stations and maximum azimuthal gap was 180o. The inversion results are checked for initial model dependence and the effect of damping factor. The reliability of the results is also evaluated in terms of derivative-weighted-sum, resolution-diagonal-elements values and checkerboard tests. The hypocenter locations of the local earthquakes have been remarkably improved by the three-dimensional velocity model obtained from the tomographic inversion. The three-dimensional velocity model shows that the Tekirdag, Central and Cinarcik Basins are characterized generally by lower Vp (3.0 - 3.5 km/s) values and most of the earthquakes across these regions are located at the depths of 10 to 17 km, about 5 km deeper than those obtained from the one-dimensional reference

  16. Nocturnal air, road, and rail traffic noise and daytime cognitive performance and annoyance.

    PubMed

    Elmenhorst, Eva-Maria; Quehl, Julia; Müller, Uwe; Basner, Mathias

    2014-01-01

    Various studies indicate that at the same noise level and during the daytime, annoyance increases in the order of rail, road, and aircraft noise. The present study investigates if the same ranking can be found for annoyance to nocturnal exposure and next day cognitive performance. Annoyance ratings and performance change during combined noise exposure were also tested. In the laboratory 72 participants were exposed to air, road, or rail traffic noise and all combinations. The number of noise events and LAS,eq were kept constant. Each morning noise annoyance questionnaires and performance tasks were administered. Aircraft noise annoyance ranked first followed by railway and road noise. A possible explanation is the longer duration of aircraft noise events used in this study compared to road and railway noise events. In contrast to road and rail traffic, aircraft noise annoyance was higher after nights with combined exposure. Pooled noise exposure data showed small but significant impairments in reaction times (6 ms) compared to nights without noise. The noise sources did not have a differential impact on performance. Combined exposure to multiple traffic noise sources did not induce stronger impairments than a single noise source. This was reflected also in low workload ratings. PMID:24437761

  17. AIR CONVECTION NOISE OF PENCIL-BEAM INTERFERMETER FOR LONG TRACE PROFILER.

    SciTech Connect

    YASHCHUK, V.V.; IRICK, S.C.; MACDOWELL, A.A.; MCKINNEY, W.R.; TAKACS, P.Z.

    2006-08-14

    In this work, we investigate the effect of air convection on laser-beam pointing noise essential for the long trace profiler (LTP). We describe this pointing error with noise power density (NPD) frequency distributions. It is shown that the NPD spectra due to air convection have a very characteristic form. In the range of frequencies from {approx}0.05 Hz to {approx}0.5 Hz, the spectra can be modeled with an inverse-power-law function. Depending on the intensity of air convection that is controlled with a resistive heater of 100 to 150 mW along a one-meter-long optical path, the power index lies between 2 and 3 at an overall rms noise of {approx}0.5 to 1 microradian. The efficiency of suppression of the convection noise by blowing air across the beam optical path is also discussed. Air-blowing leads to a white-noise-like spectrum. Air blowing was applied to the reference channel of an LTP allowing demonstration of the contribution of air convection noise to the LTP reference beam. The ability to change (with the blowing technique presented) the spectral characteristics of the beam pointing noise due to air convection allows one to investigate the contribution of the convection effect, and thus make corrections to the power spectral density spectra measured with the LTP.

  18. Air convection noise of pencil-beam interferometer for long traceprofiler

    SciTech Connect

    Yashchuk, Valeriy V.; Irick, Steve C.; MacDowell, Alastair A.; McKinney, Wayne R.; Takacs, Peter Z.

    2006-07-12

    In this work, we investigate the effect of air convection onlaser-beam pointing noise essential for the long trace profiler (LTP). Wedescribe this pointing error with noise power density (NPD) frequencydistributions. It is shown that the NPD spectra due to air convectionhave a very characteristic form. In the range of frequencies from ~;0.05Hz to ~;0.5 Hz, the spectra can be modeled with an inverse-power-lawfunction. Depending on the intensity of air convection that is controlledwith a resistive heater of 100 to 150 mW along a one-meter-long opticalpath, the power index lies between 2 and 3 at an overall rms noise of~;0.5 to 1 microradian. The efficiency of suppression of the convectionnoise by blowing air across the beam optical path is also discussed.Air-blowing leads to a white-noise-like spectrum. Air blowing was appliedto the reference channel of an LTP allowing demonstration of thecontribution of air convection noise to the LTP reference beam. Theability to change (with the blowing technique presented) the spectralcharacteristics of the beam pointing noise due to air convection allowsone to investigate the contribution of the convection effect, and thusmake corrections to the power spectral density spectra measured with theLTP.

  19. Single and Combined Effects of Air, Road, and Rail Traffic Noise on Sleep and Recuperation

    PubMed Central

    Basner, Mathias; Müller, Uwe; Elmenhorst, Eva-Maria

    2011-01-01

    Study Objective: Traffic noise disturbs sleep and may impair recuperation. There is limited information on single and combined effects of air, road, and rail traffic noise on sleep and recuperation. Design: Repeated measures. Setting: Polysomnographic laboratory study. Participants: 72 healthy subjects, mean ± standard deviation 40 ± 13 years, range 18-71 years, 32 male. Interventions: Exposure to 40, 80, or 120 rail, road, and/or air traffic noise events. Measurement and Results: Subjects were investigated for 11 consecutive nights, which included 8 noise exposure nights and one noise-free control night. Noise effects on sleep structure and continuity were subtle, even in nights with combined exposure, most likely because of habituation and an increase in arousal thresholds both within and across nights. However, cardiac arousals did not habituate across nights. Noise exposure significantly affected subjective assessments of sleep quality and recuperation, whereas objective performance was unaffected, except for a small increase in mean PVT reaction time (+4 ms, adjusted P < 0.05). Road traffic noise led to the strongest changes in sleep structure and continuity, whereas subjective assessments of sleep were worse after nights with air and rail traffic noise exposure. In contrast to daytime annoyance, cortical arousal probabilities and cardiac responses were significantly lower for air than for road and rail traffic noise (all P < 0.0001). These differences were explained by sound pressure level rise time and high frequency (> 3 kHz) noise event components. Conclusions: Road, rail, and air traffic noise differentially affect objective and subjective assessments of sleep. Differences in the degree of noise-induced sleep fragmentation between traffic modes were explained by the specific spectral and temporal composition of noise events, indicating potential targets for active and passive noise control. Field studies are needed to validate our findings in a setting

  20. [The problems of assessment of the high noise impact on the experts of the Air Force].

    PubMed

    Zinkin, V N; Sheshegov, P M

    2012-01-01

    Air Force specialists are exposed to high intensity noise levels exceeded the maximum permissible levels. Infrasound as a productive factor in accordance with the general technical requirements (OTT) Air Force-86 is not included in the list of standardized factors. The adverse acoustic environment makes the risk of occupational (sensorineural deafness) and professionally-related diseases of the nervous and cardiovascular systems. The system of physical fitness for military service in the Air Force and serving in the Air Force with high-intensity sources of noise, the system of treatment and preventive measures for adverse effects of noise and the procedure for examination of persons with diseases caused by the influence of noise are needed to be reviewed in accordance with the existing state legislative frameworks. PMID:22545451

  1. Noise Effects on Health in the Context of Air Pollution Exposure.

    PubMed

    Stansfeld, Stephen A

    2015-10-01

    For public health policy and planning it is important to understand the relative contribution of environmental noise on health compared to other environmental stressors. Air pollution is the primary environmental stressor in relation to cardiovascular morbidity and mortality. This paper reports a narrative review of studies in which the associations of both environmental noise and air pollution with health have been examined. Studies of hypertension, myocardial infarction, stroke, mortality and cognitive outcomes were included. Results suggest independent effects of environmental noise from road traffic, aircraft and, with fewer studies, railway noise on cardiovascular outcomes after adjustment for air pollution. Comparative burden of disease studies demonstrate that air pollution is the primary environmental cause of disability adjusted life years lost (DALYs). Environmental noise is ranked second in terms of DALYs in Europe and the DALYs attributed to noise were more than those attributed to lead, ozone and dioxins. In conclusion, in planning and health impact assessment environmental noise should be considered an independent contributor to health risk which has a separate and substantial role in ill-health separate to that of air pollution. PMID:26473905

  2. Noise Effects on Health in the Context of Air Pollution Exposure

    PubMed Central

    Stansfeld, Stephen A.

    2015-01-01

    For public health policy and planning it is important to understand the relative contribution of environmental noise on health compared to other environmental stressors. Air pollution is the primary environmental stressor in relation to cardiovascular morbidity and mortality. This paper reports a narrative review of studies in which the associations of both environmental noise and air pollution with health have been examined. Studies of hypertension, myocardial infarction, stroke, mortality and cognitive outcomes were included. Results suggest independent effects of environmental noise from road traffic, aircraft and, with fewer studies, railway noise on cardiovascular outcomes after adjustment for air pollution. Comparative burden of disease studies demonstrate that air pollution is the primary environmental cause of disability adjusted life years lost (DALYs). Environmental noise is ranked second in terms of DALYs in Europe and the DALYs attributed to noise were more than those attributed to lead, ozone and dioxins. In conclusion, in planning and health impact assessment environmental noise should be considered an independent contributor to health risk which has a separate and substantial role in ill-health separate to that of air pollution. PMID:26473905

  3. Annoyance due to noise and air pollution to the residents of heavily frequented streets

    NASA Technical Reports Server (NTRS)

    Wanner, H. U.; Wehrli, B.; Nemecek, J.; Turrian, V.

    1980-01-01

    The residents of different streets with varying traffic density and building density were questioned about annoyance due to traffic noise and air pollution. Results show that annoyance felt is dependent not only on the measured noise levels and/or air pollution concentrations, but that there do exist interactions between the residential quarters and annoyance. These interactions should be considered when fixing the limits and standards.

  4. Air gun impactor--a novel model of graded white matter spinal cord injury in rodents.

    PubMed

    Marcol, Wiesław; Slusarczyk, Wojciech; Gzik, Marek; Larysz-Brysz, Magdalena; Bobrowski, Michał; Grynkiewicz-Bylina, Beata; Rosicka, Paulina; Kalita, Katarzyna; Węglarz, Władysław; Barski, Jarosław J; Kotulska, Katarzyna; Labuzek, Krzysztof; Lewin-Kowalik, Joanna

    2012-10-01

    Understanding mechanisms of spinal cord injury and repair requires a reliable experimental model. We have developed a new device that produces a partial damage of spinal cord white matter by means of a precisely adjusted stream of air applied under high pressure. This procedure is less invasive than standard contusion or compression models and does not require surgical removal of vertebral bones. We investigated the effects of spinal cord injury made with our device in 29 adult rats, applying different experimental parameters. The rats were divided into three groups in respect to the applied force of the blast wave. Functional outcome and histopathological effects of the injury were analyzed during 12-week follow-up. The lesions were also examined by means of magnetic resonance imaging (MRI) scans. The weakest stimulus produced transient hindlimb paresis with no cyst visible in spinal cord MRI scans, whereas the strongest was associated with permanent neurological deficit accompanied by pathological changes resembling posttraumatic syringomyelia. Obtained data revealed that our apparatus provided a spinal cord injury animal model with structural changes very similar to that present in patients after moderate spinal cord trauma. PMID:22711195

  5. Noise emission and propagation in an air flow

    NASA Astrophysics Data System (ADS)

    Legendre, R.

    1983-01-01

    Sound propagation from a jet engine on an aircraft moving at a constant airspeed is examined in terms of the turbulent field, the near field, and the far field. The near and far fields are irrotational disturbances of a permanently adiabatic flow for which the entropy and enthalpy are the critical parameters. The propagation velocity of the noise is formulated, together with the extent of the acoustic field. The acoustic excitation is shown to dominate the extent of the acoustic field, while the pseudo-noise and the sound density are equal to the sound pressure and are not noise sources. The unsteady part of the turbulence noise is controlled by the pressure gradient, particularly that around the axes of the eddies.

  6. Spatial variation in environmental noise and air pollution in New York City.

    PubMed

    Kheirbek, Iyad; Ito, Kazuhiko; Neitzel, Richard; Kim, Jung; Johnson, Sarah; Ross, Zev; Eisl, Holger; Matte, Thomas

    2014-06-01

    Exposure to environmental noise from traffic is common in urban areas and has been linked to increased risks of adverse health effects including cardiovascular disease. Because traffic sources also produce air pollutants that increase the risk of cardiovascular morbidity, associations between traffic exposures and health outcomes may involve confounding and/or synergisms between air pollution and noise. While prior studies have characterized intraurban spatial variation in air pollution in New York City (NYC), limited data exists on the levels and spatial variation in noise levels. We measured 1-week equivalent continuous sound pressure levels (Leq) at 56 sites during the fall of 2012 across NYC locations with varying traffic intensity and building density that are routinely monitored for combustion-related air pollutants. We evaluated correlations among several noise metrics used to characterize noise exposures, including Leq during different time periods (night, day, weekday, weekend), Ldn (day-night noise), and measures of intermittent noise defined as the ratio of peak levels to median and background levels. We also examined correlations between sound pressure levels and co-located simultaneous measures of nitric oxide (NO), nitrogen dioxide (NO2), fine particulate matter (PM2.5), and black carbon (BC) as well as estimates of traffic and building density around the monitoring sites. Noise levels varied widely across the 56 monitoring sites; 1-week Leq varied by 21.6 dBA (range 59.1-80.7 dBA) with the highest levels observed during the weekday, daytime hours. Indices of average noise were well correlated with each other (r > 0.83), while indices of intermittent noise were not well correlated with average noise levels (r < 0.41). One-week Leq correlated well with NO, NO2, and EC levels (r = 0.61 to 0.68) and less so with PM2.5 levels (r = 0.45). We observed associations between 1-week noise levels and traffic intensity within 100 m of the monitoring sites (r = 0

  7. Evaluation studies of noise and air pollution during festival seasons in India.

    PubMed

    Battalwar, D G; Meshram, S U; Yenkie, M K N; Puri, P J

    2012-07-01

    The present research work is based on assessment of noise levels and ambient air quality at selected locations during festival seasons in Nagpur city. The noise levels were exceeding the permissible limits almost at every location during the festival period. The huge emissions of smoke arising out bursting of firecrackers have significantly resulted into air pollution; particularly in terms of Sulphur Dioxide (SO2) and Respirable Suspended Particulate Matter (Fine Dust). The immediate effect of increasing noise levels is impairing of hearing that may cause auditory fatigue and finally lead to deafness. PMID:24749201

  8. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.140 Section 84.140 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air...

  9. Noise Pollution

    MedlinePlus

    ... here: EPA Home Air and Radiation Noise Pollution Noise Pollution This page has moved. You should be ... epa.gov/clean-air-act-overview/title-iv-noise-pollution Local Navigation Air & Radiation Home Basic Information ...

  10. Noise reduction by the application of an air-bubble curtain in offshore pile driving

    NASA Astrophysics Data System (ADS)

    Tsouvalas, A.; Metrikine, A. V.

    2016-06-01

    Underwater noise pollution is a by-product of marine industrial operations. In particular, the noise generated when a foundation pile is driven into the soil with an impact hammer is considered to be harmful for the aquatic species. In an attempt to reduce the ecological footprint, several noise mitigation techniques have been investigated. Among the various solutions proposed, the air-bubble curtain is often applied due to its efficacy in noise reduction. In this paper, a model is proposed for the investigation of the sound reduction during marine piling when an air-bubble curtain is placed around the pile. The model consists of the pile, the surrounding water and soil media, and the air-bubble curtain which is positioned at a certain distance from the pile surface. The solution approach is semi-analytical and is based on the dynamic sub-structuring technique and the modal decomposition method. Two main results of the paper can be distinguished. First, a new model is proposed that can be used for predictions of the noise levels in a computationally efficient manner. Second, an analysis is presented of the principal mechanisms that are responsible for the noise reduction due to the application of the air-bubble curtain in marine piling. The understanding of these mechanisms turns to be crucial for the exploitation of the maximum efficiency of the system. It is shown that the principal mechanism of noise reduction depends strongly on the frequency content of the radiated sound and the characteristics of the bubbly medium. For piles of large diameter which radiate most of the acoustic energy at relatively low frequencies, the noise reduction is mainly attributed to the mismatch of the acoustic impedances between the seawater and the bubbly layer. On the contrary, for smaller piles and when the radiated acoustic energy is concentrated at frequencies close to, or higher than, the resonance frequency of the air bubbles, the sound absorption within the bubbly layer

  11. Gun Control, Gun Ownership, and Suicide Prevention.

    ERIC Educational Resources Information Center

    Lester, David

    1988-01-01

    Explored relationship between the extent of gun ownership and the strictness of gun control laws to suicide and homicide rates in the nine major geographic regions of the United States. Found gun ownership, rather than the strictness of gun control laws, was the strongest correlate of the rates of suicide and homicide by guns. (Author)

  12. Road, rail, and air transportation noise in residential and workplace neighborhoods and blood pressure (RECORD Study).

    PubMed

    Méline, Julie; Van Hulst, Andraea; Thomas, Frederique; Chaix, Basile

    2015-01-01

    Associations between road traffic noise and hypertension have been repeatedly documented, whereas associations with rail or total road, rail, and air (RRA) traffic noise have rarely been investigated. Moreover, most studies of noise in the environment have only taken into account the residential neighborhood. Finally, few studies have taken into account individual/neighborhood confounders in the relationship between noise and hypertension. We performed adjusted multilevel regression analyses using data from the 7,290 participants of the RECORD Study to investigate the associations of outdoor road, rail, air, and RRA traffic noise estimated at the place of residence, at the workplace, and in the neighborhoods around the residence and workplace with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension. Associations were documented between higher outdoor RRA and road traffic noise estimated at the workplace and a higher SBP [+1.36 mm of mercury, 95% confidence interval (CI): +0.12, +2.60 for 65-80 dB(A) vs 30-45 dB(A)] and DBP [+1.07 (95% CI: +0.28, +1.86)], after adjustment for individual/neighborhood confounders. These associations remained after adjustment for risk factors of hypertension. Associations were documented neither with rail traffic noise nor for hypertension. Associations between transportation noise at the workplace and blood pressure (BP) may be attributable to the higher levels of road traffic noise at the workplace than at the residence. To better understand why only noise estimated at the workplace was associated with BP, our future work will combine Global Positioning System (GPS) tracking, assessment of noise levels with sensors, and ambulatory monitoring of BP. PMID:26356373

  13. Road, rail, and air transportation noise in residential and workplace neighborhoods and blood pressure (RECORD Study)

    PubMed Central

    Méline, Julie; Van Hulst, Andraea; Thomas, Frederique; Chaix, Basile

    2015-01-01

    Associations between road traffic noise and hypertension have been repeatedly documented, whereas associations with rail or total road, rail, and air (RRA) traffic noise have rarely been investigated. Moreover, most studies of noise in the environment have only taken into account the residential neighborhood. Finally, few studies have taken into account individual/neighborhood confounders in the relationship between noise and hypertension. We performed adjusted multilevel regression analyses using data from the 7,290 participants of the RECORD Study to investigate the associations of outdoor road, rail, air, and RRA traffic noise estimated at the place of residence, at the workplace, and in the neighborhoods around the residence and workplace with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension. Associations were documented between higher outdoor RRA and road traffic noise estimated at the workplace and a higher SBP [+1.36 mm of mercury, 95% confidence interval (CI): +0.12, +2.60 for 65-80 dB(A) vs 30-45 dB(A)] and DBP [+1.07 (95% CI: +0.28, +1.86)], after adjustment for individual/neighborhood confounders. These associations remained after adjustment for risk factors of hypertension. Associations were documented neither with rail traffic noise nor for hypertension. Associations between transportation noise at the workplace and blood pressure (BP) may be attributable to the higher levels of road traffic noise at the workplace than at the residence. To better understand why only noise estimated at the workplace was associated with BP, our future work will combine Global Positioning System (GPS) tracking, assessment of noise levels with sensors, and ambulatory monitoring of BP. PMID:26356373

  14. Passive Underwater Noise Attenuation Using Large Encapsulated Air Bubbles.

    PubMed

    Lee, Kevin M; Wochner, Mark S; Wilson, Preston S

    2016-01-01

    Measurements demonstrating low-frequency underwater sound attenuation using arrays of large, tethered, stationary encapsulated bubbles to surround a sound source were compared with various effective medium models for the acoustic dispersion relationship in bubbly liquids. Good agreement was observed between measurements for the large bubbles (on the order of 10 cm) at frequencies below 1 kHz and a model originally intended to describe the acoustic behavior of ultrasound contrast agents. The primary goal is to use the model for designing encapsulated-bubble-based underwater noise abatement systems and to reduce uncertainty in system performance. PMID:26611010

  15. Impacts of Noise Barriers on Near-Road Air Quality

    EPA Science Inventory

    Numerous health studies show an increase in adverse health effects for populations near large roadways. A study was designed to assess traffic emission impacts on air quality near a heavily traveled highway. The portion of highway studied included a section of open field and a se...

  16. Influence of traffic-related noise and air pollution on self-reported fatigue.

    PubMed

    Jazani, Reza Khani; Saremi, Mahnaz; Rezapour, Tara; Kavousi, Amir; Shirzad, Hadi

    2015-01-01

    A growing body of evidence suggests that exposure to environmental pollutions is related to health problems. It is, however, questionable whether this condition affects working performance in occupational settings. The aim of this study is to determine the predictive value of age as well as traffic related air and noise pollutions for fatigue. 246 traffic officers participated in this study. Air pollution data were obtained from the local Air Quality Control Company. A sound level meter was used for measuring ambient noise. Fatigue was evaluated by the MFI-20 questionnaire. The general and physical scales showed the highest, while the reduced activity scale showed the lowest level of fatigue. Age had an independent direct effect on reduced activity and physical fatigue. The average of daytime equivalent noise level was between 71.63 and 88.51 dB(A). In the case of high noise exposure, older officers feel more fatigue than younger ones. Exposure to PM10 and O3 resulted in general and physical fatigue. Complex Interactions between SO2, CO and NO2 were found. Exposure to noise and some components of air pollution, especially O3 and PM10, increases fatigue. The authorities should adopt and rigorously implement environmental protection policies in order to protect people. PMID:26323778

  17. Gun control, gun ownership, and suicide prevention.

    PubMed

    Lester, D

    1988-01-01

    The relationship of the extent of gun ownership and the strictness of gun control laws to suicide and homicide rates in the nine major geographic regions of the United States was explored. Gun ownership, rather than the strictness of gun control laws, was found to be the strongest correlate of the rates of suicide and homicide by guns. Regions with a higher extent of gun ownership had higher rates of suicide and homicide by firearms. PMID:3262246

  18. Air blast circuit breaker noise and hearing loss: a multifactorial model for risk assessment.

    PubMed

    McBride, D I; Williams, S

    2000-04-01

    The assessment of the risk to hearing from impulse noise exposure may be a problem for the occupational physician because existing legislative and international noise exposure standards deal primarily with continuous noise, and are not valid in excess of the peak exposure limit of 200 pa (140 dB). Noise exposure in excess of this level, for example that due to firearms, is frequently perceived as harmful, but this is not necessarily the case, as impulse noise standards do, in fact, allow exposure with a maximum in the order of 6.3 kPa (170 dB). To illustrate this, a cross-sectional group of electrical transmission workers have been studied who were exposed to significant levels of impulse noise from air blast circuit breakers and firearms. Important hearing loss factors have been identified by means of a specially designed questionnaire. Using the Health & Safety Executive definition, the risk of hearing loss was determined by calculating prevalence odds ratios (ORs) for exposure to these factors. The OR for those with fewer than eight unprotected air blast circuit breaker exposures was 2.27 (95% confidence interval (CI), 1.01-5.08), whilst for those with more than eight exposures the OR was 2.10 (95% CI, 0.97-4.54). For firearm exposure, ORs of 1.61 (95% CI, 0.95-2.74) were noted in the medium exposure group and 2.05 (95% CI, 1.08-3.86) in the high exposure group. When all the factors were included in the model, the most significant factor was age. The study gives support to the impulse noise exposure criteria, confirming the borderline risk from air blast circuit breaker noise exposure and the relative safety of moderate gunfire exposure. PMID:10912360

  19. FEATURE 1, SMALL GUN POSITION, VIEW FACING NORTH. Naval ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 1, SMALL GUN POSITION, VIEW FACING NORTH. - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Small Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  20. FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING SOUTH. - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Large Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  1. FEATURE C. MACHINE GUN POSITION WITH REMNANT OF MOUNT, VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE C. MACHINE GUN POSITION WITH REMNANT OF MOUNT, VIEW FACING SOUTH-SOUTHEAST. - Naval Air Station Barbers Point, Battery-Machine Gun Positions, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  2. 6. INTERIOR DETAIL OF GUN MOUNT ON TERRACE, LOOKING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. INTERIOR DETAIL OF GUN MOUNT ON TERRACE, LOOKING EAST (1992). - Wright-Patterson Air Force Base, Area B, Building 22, Armament Laboratory & Gun Range, On flightline between Tenth & Eleventh Streets, Dayton, Montgomery County, OH

  3. FEATURE A. CONCRETE ANTIAIRCRAFT GUN POSITION, VIEW FACING NORTHNORTHEAST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE A. CONCRETE ANTI-AIRCRAFT GUN POSITION, VIEW FACING NORTH-NORTHEAST. - Naval Air Station Barbers Point, Battery-Anti-Aircraft Gun Position, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  4. FEATURE 1, SMALL GUN POSITION, VIEW FACING NORTH, (with scale ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 1, SMALL GUN POSITION, VIEW FACING NORTH, (with scale stick). - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Small Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  5. FEATURE B. MACHINE GUN POSITION WITH LEWIS MOUNT, VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE B. MACHINE GUN POSITION WITH LEWIS MOUNT, VIEW FACING NORTHWEST. - Naval Air Station Barbers Point, Battery-Machine Gun Positions, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  6. FEATURE A. CONCRETE ANTIAIRCRAFT GUN POSITION, VIEW FACING NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE A. CONCRETE ANTI-AIRCRAFT GUN POSITION, VIEW FACING NORTH - NORTHEAST (with scale stick). - Naval Air Station Barbers Point, Battery-Anti-Aircraft Gun Position, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  7. FEATURE A. CONCRETE ANTIAIRCRAFT GUN POSITION, SHOWING CORAL RUBBLE BERM, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE A. CONCRETE ANTI-AIRCRAFT GUN POSITION, SHOWING CORAL RUBBLE BERM, VIEW FACING SOUTHEAST. - Naval Air Station Barbers Point, Battery-Anti-Aircraft Gun Position, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  8. FEATURE B. MACHINE GUN POSITION WITH LEWIS MOUNT, VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE B. MACHINE GUN POSITION WITH LEWIS MOUNT, VIEW FACING NORTHWEST (with scale stick). - Naval Air Station Barbers Point, Battery-Machine Gun Positions, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  9. Noise

    MedlinePlus

    Noise is all around you, from televisions and radios to lawn mowers and washing machines. Normally, you ... sensitive structures of the inner ear and cause noise-induced hearing loss. More than 30 million Americans ...

  10. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and...

  11. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.202 Section 84.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Chemical...

  12. Spectrometer gun

    DOEpatents

    Waechter, David A.; Wolf, Michael A.; Umbarger, C. John

    1985-01-01

    A hand-holdable, battery-operated, microprocessor-based spectrometer gun includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

  13. Spectrometer gun

    DOEpatents

    Waechter, D.A.; Wolf, M.A.; Umbarger, C.J.

    1981-11-03

    A hand-holdable, battery-operated, microprocessor-based spectrometer gun is described that includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

  14. The Covariance between Air Pollution Annoyance and Noise Annoyance, and Its Relationship with Health-Related Quality of Life

    PubMed Central

    Shepherd, Daniel; Dirks, Kim; Welch, David; McBride, David; Landon, Jason

    2016-01-01

    Air pollution originating from road traffic is a known risk factor of respiratory and cardiovascular disease (both in terms of chronic and acute effects). While adverse effects on cardiovascular health have also been linked with noise (after controlling for air pollution), noise exposure has been commonly linked to sleep impairment and negative emotional reactions. Health is multi-faceted, both conceptually and operationally; Health-Related Quality of Life (HRQOL) is one of many measures capable of probing health. In this study, we examine pre-collected data from postal surveys probing HRQOL obtained from a variety of urban, suburban, and rural contexts across the North Island of New Zealand. Analyses focus on the covariance between air pollution annoyance and noise annoyances, and their independent and combined effects on HRQOL. Results indicate that the highest ratings of air pollution annoyance and noise annoyances were for residents living close to the motorway, while the lowest were for rural residents. Most of the city samples indicated no significant difference between air pollution- and noise-annoyance ratings, and of all of the correlations between air pollution- and noise-annoyance, the highest were found in the city samples. These findings suggest that annoyance is driven by exposure to environmental factors and not personality characteristics. Analysis of HRQOL indicated that air pollution annoyance predicts greater variability in the physical HRQOL domain while noise annoyance predicts greater variability in the psychological, social and environmental domains. The lack of an interaction effect between air pollution annoyance and noise annoyance suggests that air pollution and noise impact on health independently. These results echo those obtained from objective measures of health and suggest that mitigation of traffic effects should address both air and noise pollution. PMID:27509512

  15. The Covariance between Air Pollution Annoyance and Noise Annoyance, and Its Relationship with Health-Related Quality of Life.

    PubMed

    Shepherd, Daniel; Dirks, Kim; Welch, David; McBride, David; Landon, Jason

    2016-01-01

    Air pollution originating from road traffic is a known risk factor of respiratory and cardiovascular disease (both in terms of chronic and acute effects). While adverse effects on cardiovascular health have also been linked with noise (after controlling for air pollution), noise exposure has been commonly linked to sleep impairment and negative emotional reactions. Health is multi-faceted, both conceptually and operationally; Health-Related Quality of Life (HRQOL) is one of many measures capable of probing health. In this study, we examine pre-collected data from postal surveys probing HRQOL obtained from a variety of urban, suburban, and rural contexts across the North Island of New Zealand. Analyses focus on the covariance between air pollution annoyance and noise annoyances, and their independent and combined effects on HRQOL. Results indicate that the highest ratings of air pollution annoyance and noise annoyances were for residents living close to the motorway, while the lowest were for rural residents. Most of the city samples indicated no significant difference between air pollution- and noise-annoyance ratings, and of all of the correlations between air pollution- and noise-annoyance, the highest were found in the city samples. These findings suggest that annoyance is driven by exposure to environmental factors and not personality characteristics. Analysis of HRQOL indicated that air pollution annoyance predicts greater variability in the physical HRQOL domain while noise annoyance predicts greater variability in the psychological, social and environmental domains. The lack of an interaction effect between air pollution annoyance and noise annoyance suggests that air pollution and noise impact on health independently. These results echo those obtained from objective measures of health and suggest that mitigation of traffic effects should address both air and noise pollution. PMID:27509512

  16. Air backed mandrel type fiber optic hydrophone with low noise floor

    NASA Astrophysics Data System (ADS)

    Rajesh, R.; V, Sreehari C.; N, Praveen Kumar; Awasthi, R. L.; K, Vivek; B, Vishnu M.; Santhanakrishnan, T.; Moosad, K. P. B.; Mathew, Basil

    2014-10-01

    Low noise fiber optic hydrophone based on optical fiber coil wound on air-backed mandrel was developed. The sensor can be effectively used for underwater acoustic sensing. The design and characterization of the hydrophone is illustrated in this paper. A fiber Mach-Zehnder Interferometer (MZI) was developed and coupled with a Distributed Feedback (DFB) fiber laser source and an optical phase demodulation system, with an active modulation in one of the arms. The sensor head design was optimized to achieve noise spectral density <10 μrad/√Hz, for yielding sufficient sensitivity to sense acoustic pressure close to Deep Sea Sate Zero (DSS0).

  17. Airport noise complaint patterns and interviews of frequent complainers at two major air carrier airports

    NASA Astrophysics Data System (ADS)

    Jaggers, Nicholas; Eiff, Gary

    2005-09-01

    The complex and highly sensitive topic of aircraft noise and population annoyance continues to be a major inhibitor to airport development plans. The projected growth of air travel necessitates expanded capacity at many existing airports and the development and construction of new airports in order to accommodate burgeoning traveler needs. Concerns by citizens near major airports about their economic, health, and social welfare continue to generate community and individual declarations of annoyance and concern which threaten timely solutions to airport expansion plans. A deeper understanding of the nature of these concerns is important to more effectively cope with airport expansion concerns among adjacent communities and surrounding neighbors. This study analyzed existing noise complaints registered at Denver International Airport (DEN) and Fort Lauderdale/Hollywood International Airport (FLL) in an attempt to gain greater understanding of noise complaint drivers and public annoyance. Interviews of frequent complainers were utilized in order to gain richer data concerning individual annoyance issues.

  18. Air Force procedure for predicting aircraft noise around airbases: Airbase operations program (BASEOPS) description

    NASA Astrophysics Data System (ADS)

    Lee, Robert A.; Mohlman, Henry T.

    1990-01-01

    A user manual is presented for the BASEOPS 3.00 program developed by AAMRL/BBE. The installation, use and limitations of this program is described. BASEOPS is the menu driven computerized airbase operations input program used in doing airbase noise assessments under the USAF Air Installation Compatible Use Zone (AICUZ) program. BASEOPS will create a file that can be directly interfaced to the NOISEMAP 6.0 program, used to calculate the total noise exposure from these input operations. BASEOPS contains default performance profiles (takeoff and landing) for Military Transient and Civil aircraft. The program also allows the user to create a NOISEMAP input file for any subset of the input data through a Global Editing Menu. This can be used for quickly creating multiple noise analyses for different operational input scenarios.

  19. Noise reduction evaluation of grids in a supersonic air stream with application to Space Shuttle

    NASA Technical Reports Server (NTRS)

    Seiner, J. M.; Manning, J. C.; Nystrom, P.; Pao, S. P.

    1977-01-01

    Near field acoustic measurements were obtained for a model supersonic air jet perturbed by a screen. Noise reduction potential in the vicinity of the space shuttle vehicle during ground launch when the rocket exhaust flow is perturbed by a grid was determined. Both 10 and 12 mesh screens were utilized for this experiment, and each exhibited a noise reduction only at very low frequencies in the near field forward arc. A power spectrum analysis revealed that a modest reduction of from 3 to 5 decibels exists below a Strouhal number S sub t = 0.11. Above S sub t = 0.11 screen harmonics increased the observed sound pressure level. The favorable noise reductions obtained with screens for S sub t 0.11 may be of substantial interest for the space shuttle at ground launch.

  20. USAF Bioenvironmental Noise Data Handbook. Volume 167: MA-3M air conditioner

    NASA Astrophysics Data System (ADS)

    Rau, T. H.

    1982-06-01

    The MA-3M is an electric motor-driven air conditioner designed to cool electronic equipment on aircraft during ground maintenance. This report provides measured and extrapolated data defining the bioacoustic environments produced by this unit operating at a normal rated condition. Near-field data are reported for 37 locations in a wide variety of physical and psychoacoustic measures: overall and band sound pressure levels, C-weighted and A-weighted sound levels, preferred speech interference levels, perceived noise levels, and limiting times for total daily exposure of personnel with and without standard Air Force ear protectors.

  1. Impact of Diwali celebrations on urban air and noise quality in Delhi City, India.

    PubMed

    Mandal, Papiya; Prakash, Mamta; Bassin, J K

    2012-01-01

    A study was conducted in the residential areas of Delhi, India, to assess the variation in ambient air quality and ambient noise levels during pre-Diwali month (DM), Diwali day (DD) and post-Diwali month during the period 2006 to 2008. The use of fireworks during DD showed 1.3 to 4.0 times increase in concentration of respirable particulate matter (PM(10)) and 1.6 to 2.5 times increase in concentration of total suspended particulate matter (TSP) than the concentration during DM. There was a significant increase in sulfur dioxide (SO(2)) concentration but the concentration of nitrogen dioxide (NO(2)) did not show any considerable variation. Ambient noise level were 1.2 to 1.3 times higher than normal day. The study also showed a strong correlation between PM(10) and TSP (R (2) ≥ 0.9) and SO(2) and NO(2) (R (2) ≥ 0.9) on DD. The correlation between noise level and gaseous pollutant were moderate (R (2) ≥ 0.5). The average concentration of the pollutants during DD was found higher in 2007 which could be due to adverse meteorological conditions. The statistical interpretation of data indicated that the celebration of Diwali festival affects the ambient air and noise quality. The study would provide public awareness about the health risks associated with the celebrations of Diwali festival so as to take proper precautions. PMID:21424668

  2. Spot-Welding Gun Is Easy To Use

    NASA Technical Reports Server (NTRS)

    Morgan, Gene E.; Nguyen, Francis H.

    1991-01-01

    Electrical-resistance spot-welding gun designed to produce more welds per unit time by decreasing technician's effort and fatigue. Vacuum cups on frame secure welding gun to workpiece while compressed air drives welding tip against workpiece to make spot resistance weld. When weld completed, vacuum in frame cups released so frame and gun moved to position of next spot weld.

  3. Improved DC Gun Insulator

    SciTech Connect

    M.L. Neubauer, K.B. Beard, R. Sah, C. Hernandez-Garcia, G. Neil

    2009-05-01

    Many user facilities such as synchrotron light sources and free electron lasers require accelerating structures that support electric fields of 10-100 MV/m, especially at the start of the accelerator chain where ceramic insulators are used for very high gradient DC guns. These insulators are difficult to manufacture, require long commissioning times, and have poor reliability, in part because energetic electrons bury themselves in the ceramic, creating a buildup of charge and causing eventual puncture. A novel ceramic manufacturing process is proposed. It will incorporate bulk resistivity in the region where it is needed to bleed off accumulated charge caused by highly energetic electrons. This process will be optimized to provide an appropriate gradient in bulk resistivity from the vacuum side to the air side of the HV standoff ceramic cylinder. A computer model will be used to determine the optimum cylinder dimensions and required resistivity gradient for an example RF gun application. A ceramic material example with resistivity gradient appropriate for use as a DC gun insulator will be fabricated by glazing using doping compounds and tested.

  4. ION GUN

    DOEpatents

    Dandl, R.A.

    1961-10-24

    An ion gun is described for the production of an electrically neutral ionized plasma. The ion gun comprises an anode and a cathode mounted in concentric relationship with a narrow annulus between. The facing surfaces of the rear portions of the anode and cathode are recessed to form an annular manifold. Positioned within this manifold is an annular intermediate electrode aligned with the an nulus between the anode and cathode. Gas is fed to the manifold and an arc discharge is established between the anode and cathode. The gas is then withdrawn from the manifold through the annulus between the anode and cathode by a pressure differential. The gas is then ionized by the arc discharge across the annulus. The ionized gas is withdrawn from the annulus by the combined effects of the pressure differential and a collimating magnetic field. In a 3000 gauss magnetic field, an arc voltage of 1800 volts, and an arc current of 0.2 amp, a plasma of about 3 x 10/sup 11/ particles/cc is obtained. (AEC)

  5. ELECTRON GUN

    DOEpatents

    Christofilos, N.C.; Ehlers, K.W.

    1960-04-01

    A pulsed electron gun capable of delivering pulses at voltages of the order of 1 mv and currents of the order of 100 amperes is described. The principal novelty resides in a transformer construction which is disposed in the same vacuum housing as the electron source and accelerating electrode structure of the gun to supply the accelerating potential thereto. The transformer is provided by a plurality of magnetic cores disposed in circumferentially spaced relation and having a plurality of primary windings each inductively coupled to a different one of the cores, and a helical secondary winding which is disposed coaxially of the cores and passes therethrough in circumferential succession. Additional novelty resides in the disposition of the electron source cathode filament input leads interiorly of the transformer secondary winding which is hollow, as well as in the employment of a half-wave filament supply which is synchronously operated with the transformer supply such that the transformer is pulsed during the zero current portions of the half-wave cycle.

  6. Gun ownership and social gun culture.

    PubMed

    Kalesan, Bindu; Villarreal, Marcos D; Keyes, Katherine M; Galea, Sandro

    2016-06-01

    We assessed gun ownership rates in 2013 across the USA and the association between exposure to a social gun culture and gun ownership. We used data from a nationally representative sample of 4000 US adults, from 50 states and District of Columbia, aged >18 years to assess gun ownership and social gun culture performed in October 2013. State-level firearm policy information was obtained from the Brady Law Center and Injury Prevention and Control Center. One-third of Americans reported owning a gun, ranging from 5.2% in Delaware to 61.7% in Alaska. Gun ownership was 2.25-times greater among those reporting social gun culture (PR=2.25, 95% CI 2.02 to 2.52) than those who did not. In conclusion, we found strong association between social gun culture and gun ownership. Gun cultures may need to be considered for public health strategies that aim to change gun ownership in the USA. PMID:26124073

  7. Encyclopedia of Gun Control and Gun Rights.

    ERIC Educational Resources Information Center

    Utter, Glenn H.

    This reference volume provides information on gun control and gun rights, including resources on the debate surrounding the Second Amendment and individuals and organizations focused on gun issues, along with statutes, court cases, events, and publications surrounding this current topic. Highlighted are the important organizations and their…

  8. Influence of solid noise barriers on near-road and on-road air quality

    NASA Astrophysics Data System (ADS)

    Baldauf, Richard W.; Isakov, Vlad; Deshmukh, Parikshit; Venkatram, Akula; Yang, Bo; Zhang, K. Max

    2016-03-01

    Public health concerns regarding adverse health effects for populations spending significant amounts of time near high traffic roadways has increased substantially in recent years. Roadside features, including solid noise barriers, have been investigated as potential methods that can be implemented in a relatively short time period to reduce air pollution exposures from nearby traffic. A field study was conducted to determine the influence of noise barriers on both on-road and downwind pollutant concentrations near a large highway in Phoenix, Arizona, USA. Concentrations of nitrogen dioxide, carbon monoxide, ultrafine particles, and black carbon were measured using a mobile platform and fixed sites along two limited-access stretches of highway that contained a section of noise barrier and a section with no noise barrier at-grade with the surrounding terrain. Results of the study showed that pollutant concentrations behind the roadside barriers were significantly lower relative to those measured in the absence of barriers. The reductions ranged from 50% within 50 m from the barrier to about 30% as far as 300 m from the barrier. Reductions in pollutant concentrations generally began within the first 50 m of the barrier edge; however, concentrations were highly variable due to vehicle activity behind the barrier and along nearby urban arterial roadways. The concentrations on the highway, upwind of the barrier, varied depending on wind direction. Overall, the on-road concentrations in front of the noise barrier were similar to those measured in the absence of the barrier, contradicting previous modeling results that suggested roadside barriers increase pollutant levels on the road. Thus, this study suggests that noise barriers do reduce potential pollutant exposures for populations downwind of the road, and do not likely increase exposures to traffic-related pollutants for vehicle passengers on the highway.

  9. Wavelet based de-noising of breath air absorption spectra profiles for improved classification by principal component analysis

    NASA Astrophysics Data System (ADS)

    Kistenev, Yu. V.; Shapovalov, A. V.; Borisov, A. V.; Vrazhnov, D. A.; Nikolaev, V. V.; Nikiforova, O. Yu.

    2015-11-01

    The comparison results of different mother wavelets used for de-noising of model and experimental data which were presented by profiles of absorption spectra of exhaled air are presented. The impact of wavelets de-noising on classification quality made by principal component analysis are also discussed.

  10. Proximity to Traffic, Ambient Air Pollution, and Community Noise in Relation to Incident Rheumatoid Arthritis

    PubMed Central

    Koehoorn, Mieke; Tamburic, Lillian; Davies, Hugh W.; Brauer, Michael

    2014-01-01

    Background: The risk of rheumatoid arthritis (RA) has been associated with living near traffic; however, there is evidence suggesting that air pollution may not be responsible for this association. Noise, another traffic-generated exposure, has not been studied as a risk factor for RA. Objectives: We investigated proximity to traffic, ambient air pollution, and community noise in relation to RA in the Vancouver and Victoria regions of British Columbia, Canada. Methods: Cases and controls were identified in a cohort of adults that was assembled using health insurance registration records. Incident RA cases from 1999 through 2002 were identified by diagnostic codes in combination with prescriptions and type of physician (e.g., rheumatologist). Controls were matched to RA cases by age and sex. Environmental exposures were assigned to each member of the study population by their residential postal code(s). We estimated relative risks using conditional logistic regression, with additional adjustment for median income at the postal code. Results: RA incidence was increased with proximity to traffic, with an odds ratio (OR) of 1.37 (95% CI: 1.11, 1.68) for residence ≤ 50 m from a highway compared with residence > 150 m away. We found no association with traffic-related exposures such as PM2.5, nitrogen oxides, or noise. Ground-level ozone, which was highest in suburban areas, was associated with an increased risk of RA (OR = 1.26; 95% CI: 1.18, 1.36 per interquartile range increase). Conclusions: Our study confirms a previously observed association of RA risk with proximity to traffic and suggests that neither noise levels nor traffic-related air pollutants are responsible for this relationship. Additional investigation of neighborhood and individual correlates of residence near roadways may provide new insight into risk factors for RA. Citation: De Roos AJ, Koehoorn M, Tamburic L, Davies HW, Brauer M. 2014. Proximity to traffic, ambient air pollution, and community

  11. Modeling the impact of solid noise barriers on near road air quality

    NASA Astrophysics Data System (ADS)

    Venkatram, Akula; Isakov, Vlad; Deshmukh, Parikshit; Baldauf, Richard

    2016-09-01

    Studies based on field measurements, wind tunnel experiments, and controlled tracer gas releases indicate that solid, roadside noise barriers can lead to reductions in downwind near-road air pollutant concentrations. A tracer gas study showed that a solid barrier reduced pollutant concentrations as much as 80% next to the barrier relative to an open area under unstable meteorological conditions, which corresponds to typical daytime conditions when residents living or children going to school near roadways are most likely to be exposed to traffic emissions. The data from this tracer gas study and a wind tunnel simulation were used to develop a model to describe dispersion of traffic emissions near a highway in the presence of a solid noise barrier. The model is used to interpret real-world data collected during a field study conducted in a complex urban environment next to a large highway in Phoenix, Arizona, USA. We show that the analysis of the data with the model yields useful information on the emission factors and the mitigation impact of the barrier on near-road air quality. The estimated emission factors for the four species, ultrafine particles, CO, NO2, and black carbon, are consistent with data cited in the literature. The results suggest that the model accounted for reductions in pollutant concentrations from a 4.5 m high noise barrier, ranging from 40% next to the barrier to 10% at 300 m from the barrier.

  12. A PIV Study of Slotted Air Injection for Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda S.; Wernet, Mark P.

    2012-01-01

    Results from acoustic and Particle Image Velocimetry (PIV) measurements are presented for single and dual-stream jets with fluidic injection on the core stream. The fluidic injection nozzles delivered air to the jet through slots on the interior of the nozzle at the nozzle trailing edge. The investigations include subsonic and supersonic jet conditions. Reductions in broadband shock noise and low frequency mixing noise were obtained with the introduction of fluidic injection on single stream jets. Fluidic injection was found to eliminate shock cells, increase jet mixing, and reduce turbulent kinetic energy levels near the end of the potential core. For dual-stream subsonic jets, the introduction of fluidic injection reduced low frequency noise in the peak jet noise direction and enhanced jet mixing. For dual-stream jets with supersonic fan streams and subsonic core streams, the introduction of fluidic injection in the core stream impacted the jet shock cell structure but had little effect on mixing between the core and fan streams.

  13. Effect of long-term outdoor air pollution and noise on cognitive and psychological functions in adults.

    PubMed

    Tzivian, Lilian; Winkler, Angela; Dlugaj, Martha; Schikowski, Tamara; Vossoughi, Mohammad; Fuks, Kateryna; Weinmayr, Gudrun; Hoffmann, Barbara

    2015-01-01

    It has been hypothesized that air pollution and ambient noise might impact neurocognitive function. Early studies mostly investigated the associations of air pollution and ambient noise exposure with cognitive development in children. More recently, several studies investigating associations with neurocognitive function, mood disorders, and neurodegenerative disease in adult populations were published, yielding inconsistent results. The purpose of this review is to summarize the current evidence on air pollution and noise effects on mental health in adults. We included studies in adult populations (≥18 years old) published in English language in peer-reviewed journals. Fifteen articles related to long-term effects of air pollution and eight articles on long-term effects of ambient noise were extracted. Both exposures were separately shown to be associated with one or several measures of global cognitive function, verbal and nonverbal learning and memory, activities of daily living, depressive symptoms, elevated anxiety, and nuisance. No study considered both exposures simultaneously and few studies investigated progression of neurocognitive decline or psychological factors. The existing evidence generally supports associations of environmental factors with mental health, but does not suffice for an overall conclusion about the independent effect of air pollution and noise. There is a need for studies investigating simultaneously air pollution and noise exposures in association mental health, for longitudinal studies to corroborate findings from cross-sectional analyses, and for parallel toxicological and epidemiological studies to elucidate mechanisms and pathways of action. PMID:25242804

  14. The Gun Dispute.

    ERIC Educational Resources Information Center

    Spitzer, Robert J.

    1999-01-01

    Explores the debate over gun ownership and gun control in the United States, focusing on the historic place of guns in U.S. society. The current national mood is more receptive than ever to restricting and regulating adolescent access to guns in light of recent school shootings. (SLD)

  15. Gun Sales. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Minimal federal regulations on firearm sales have facilitated the proliferation of guns, gun owners, and gun dealers in the United States. This fact sheet offers data on the growing number of firearm dealers, the relative ease of obtaining and keeping a license to sell guns from the Federal Bureau of Alcohol, Tobacco, and Firearms, the lack of…

  16. High-Resolution Analysis of Seismic Air Gun Impulses and Their Reverberant Field as Contributors to an Acoustic Environment.

    PubMed

    Guerra, Melania; Dugan, Peter J; Ponirakis, Dimitri W; Popescu, Marian; Shiu, Yu; Rice, Aaron N; Clark, Christopher W

    2016-01-01

    In September and October 2011, a seismic survey took place in Baffin Bay, Western Greenland, in close proximity to a marine protected area (MPA). As part of the mitigation effort, five bottom-mounted marine acoustic recording units (MARUs) collected data that were used for the purpose of measuring temporal and spectral features from each impulsive event, providing a high-resolution record of seismic reverberation persistent after the direct impulse. Results were compared with ambient-noise levels as computed after the seismic survey to evidence that as a consequence of a series of repeating seismic impulses, sustained elevated levels create the potential for masking. PMID:26610981

  17. Spatial and temporal associations of road traffic noise and air pollution in London: Implications for epidemiological studies.

    PubMed

    Fecht, Daniela; Hansell, Anna L; Morley, David; Dajnak, David; Vienneau, Danielle; Beevers, Sean; Toledano, Mireille B; Kelly, Frank J; Anderson, H Ross; Gulliver, John

    2016-03-01

    Road traffic gives rise to noise and air pollution exposures, both of which are associated with adverse health effects especially for cardiovascular disease, but mechanisms may differ. Understanding the variability in correlations between these pollutants is essential to understand better their separate and joint effects on human health. We explored associations between modelled noise and air pollutants using different spatial units and area characteristics in London in 2003-2010. We modelled annual average exposures to road traffic noise (LAeq,24h, Lden, LAeq,16h, Lnight) for ~190,000 postcode centroids in London using the UK Calculation of Road Traffic Noise (CRTN) method. We used a dispersion model (KCLurban) to model nitrogen dioxide, nitrogen oxide, ozone, total and the traffic-only component of particulate matter ≤2.5μm and ≤10μm. We analysed noise and air pollution correlations at the postcode level (~50 people), postcodes stratified by London Boroughs (~240,000 people), neighbourhoods (Lower layer Super Output Areas) (~1600 people), 1km grid squares, air pollution tertiles, 50m, 100m and 200m in distance from major roads and by deprivation tertiles. Across all London postcodes, we observed overall moderate correlations between modelled noise and air pollution that were stable over time (Spearman's rho range: |0.34-0.55|). Correlations, however, varied considerably depending on the spatial unit: largest ranges were seen in neighbourhoods and 1km grid squares (both Spearman's rho range: |0.01-0.87|) and was less for Boroughs (Spearman's rho range: |0.21-0.78|). There was little difference in correlations between exposure tertiles, distance from road or deprivation tertiles. Associations between noise and air pollution at the relevant geographical unit of analysis need to be carefully considered in any epidemiological analysis, in particular in complex urban areas. Low correlations near roads, however, suggest that independent effects of road noise and

  18. The spatial relationship between traffic-generated air pollution and noise in 2 US cities☆

    PubMed Central

    Allen, Ryan W.; Davies, Hugh; Cohen, Martin A.; Mallach, Gary; Kaufman, Joel D.; Adar, Sara D.

    2011-01-01

    Traffic-generated air pollution and noise have both been linked to cardiovascular morbidity. Since traffic is a shared source, there is potential for correlated exposures that may lead to confounding in epidemiologic studies. As part of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), 2-week NO and NO2 concentrations were measured at up to 105 locations, selected primarily to characterize gradients near major roads, in each of 9 US communities. We measured 5-min A-weighted equivalent continuous sound pressure levels (Leq) and ultrafine particle (UFP) counts at a subset of these NO/NO2 monitoring locations in Chicago, IL (N = 69 in December 2006; N = 36 in April 2007) and Riverside County, CA (N = 46 in April 2007). Leq and UFP were measured during non-“rush hour” periods (10:00–16:00) to maximize comparability between measurements. We evaluated roadway proximity exposure surrogates in relation to the measured levels, estimated noise–air pollution correlation coefficients, and evaluated the impact of regional-scale pollution gradients, wind direction, and roadway proximity on the correlations. Five-minute Leq measurements in December 2006 and April 2007 were highly correlated (r = 0.84), and measurements made at different times of day were similar (coefficients of variation: 0.5–13%), indicating that 5-min measurements are representative of long-term Leq. Binary and continuous roadway proximity metrics characterized Leq as well or better than NO or NO2. We found strong regional-scale gradients in NO and NO2, particularly in Chicago, but only weak regional-scale gradients in Leq and UFP. Leq was most consistently correlated with NO, but the correlations were moderate (0.20–0.60). After removing the influence of regional-scale gradients the correlations generally increased (Leq–NO: r = 0.49–0.62), and correlations downwind of major roads (Leq–NO: r = 0.53–0.74) were consistently higher than those upwind (0.35–0.65). There

  19. High pressure air jet in the endoscopic preparation room: risk of noise exposure on occupational health.

    PubMed

    Chiu, King-Wah; Lu, Lung-Sheng; Wu, Cheng-Kun

    2015-01-01

    After high-level disinfection of gastrointestinal endoscopes, they are hung to dry in order to prevent residual water droplets impact on patient health. To allow for quick drying and clinical reuse, some endoscopic units use a high pressure air jet (HPAJ) to remove the water droplets on the endoscopes. The purpose of this study was to evaluate the excessive noise exposure with the use of HPAJ in endoscopic preparation room and to investigate the risk to occupational health. Noise assessment was taken during 7 automatic endoscopic reprocessors (AERs) and combined with/without HPAJ use over an 8-hour time-weighted average (TWA). Analytical procedures of the NIOSH and the ISO for noise-induced hearing loss were estimated to develop analytic models. The peak of the noise spectrum of combined HPAJ and 7 AERs was significantly higher than that of the 7 AERs alone (108.3 ± 1.36 versus 69.3 ± 3.93 dBA, P < 0.0001). The risk of hearing loss (HL > 2.5 dB) was 2.15% at 90 dBA, 11.6% at 95 dBA, and 51.3% at 100 dBA. The odds ratio was 49.1 (95% CI: 11.9 to 203.6). The noise generated by the HPAJ to work over TWA seriously affected the occupational health and safety of those working in an endoscopic preparation room. PMID:25710009

  20. 77 FR 18297 - Air Traffic Noise, Fuel Burn, and Emissions Modeling Using the Aviation Environmental Design Tool...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ... Federal Aviation Administration Air Traffic Noise, Fuel Burn, and Emissions Modeling Using the Aviation... methodology for performing air quality analysis modeling for aviation sources.'' Section 2.4d states that... using the most recent EDMS model available at the start of the environmental analysis process.'' ]...

  1. Air flow measurement techniques applied to noise reduction of a centrifugal blower

    NASA Astrophysics Data System (ADS)

    Laage, John W.; Armstrong, Ashli J.; Eilers, Daniel J.; Olsen, Michael G.; Mann, J. Adin

    2005-09-01

    The air flow in a centrifugal blower was studied using a variety of flow and sound measurement techniques. The flow measurement techniques employed included Particle Image Velocimetry (PIV), pitot tubes, and a five hole spherical probe. PIV was used to measure instantaneous and ensemble-averaged velocity fields over large area of the outlet duct as a function of fan position, allowing for the visualization of the flow as it leave the fan blades and progressed downstream. The results from the flow measurements were reviewed along side the results of the sound measurements with the goal of identifying sources of noise and inefficiencies in flow performance. The radiated sound power was divided into broadband and tone noise and measures of the flow. The changes in the tone and broadband sound were compared to changes in flow quantities such as the turbulent kinetic energy and Reynolds stress. Results for each method will be presented to demonstrate the strengths of each flow measurement technique as well as their limitations. Finally, the role that each played in identifying noise sources is described.

  2. Annoyance Caused by Noise and Air Pollution during Pregnancy: Associated Factors and Correlation with Outdoor NO2 and Benzene Estimations

    PubMed Central

    Fernández-Somoano, Ana; Llop, Sabrina; Aguilera, Inmaculada; Tamayo-Uria, Ibon; Martínez, María Dolores; Foraster, Maria; Ballester, Ferran; Tardón, Adonina

    2015-01-01

    This study aimed to describe the degree of annoyance among pregnant women in a Spanish cohort and to examine associations with proximity to traffic, NO2 and benzene exposure. We included 2457 participants from the Spanish Childhood and Environment study. Individual exposures to outdoor NO2 and benzene were estimated, temporally adjusted for pregnancy. Interviews about sociodemographic variables, noise and air pollution were carried out. Levels of annoyance were assessed using a scale from 0 (none) to 10 (strong and unbearable); a level of 8 to 10 was considered high. The reported prevalence of high annoyance levels from air pollution was 11.2% and 15.0% from noise; the two variables were moderately correlated (0.606). Significant correlations between NO2 and annoyance from air pollution (0.154) and that from noise (0.181) were observed. Annoyance owing to noise and air pollution had a low prevalence in our Spanish population compared with other European populations. Both factors were associated with proximity to traffic. In multivariate models, annoyance from air pollution was related to NO2, building age, and country of birth; annoyance from noise was only related to the first two. The health burden of these exposures can be increased by stress caused by the perception of pollution sources. PMID:26095869

  3. Annoyance Caused by Noise and Air Pollution during Pregnancy: Associated Factors and Correlation with Outdoor NO2 and Benzene Estimations.

    PubMed

    Fernández-Somoano, Ana; Llop, Sabrina; Aguilera, Inmaculada; Tamayo-Uria, Ibon; Martínez, María Dolores; Foraster, Maria; Ballester, Ferran; Tardón, Adonina

    2015-06-01

    This study aimed to describe the degree of annoyance among pregnant women in a Spanish cohort and to examine associations with proximity to traffic, NO2 and benzene exposure. We included 2457 participants from the Spanish Childhood and Environment study. Individual exposures to outdoor NO2 and benzene were estimated, temporally adjusted for pregnancy. Interviews about sociodemographic variables, noise and air pollution were carried out. Levels of annoyance were assessed using a scale from 0 (none) to 10 (strong and unbearable); a level of 8 to 10 was considered high. The reported prevalence of high annoyance levels from air pollution was 11.2% and 15.0% from noise; the two variables were moderately correlated (0.606). Significant correlations between NO2 and annoyance from air pollution (0.154) and that from noise (0.181) were observed. Annoyance owing to noise and air pollution had a low prevalence in our Spanish population compared with other European populations. Both factors were associated with proximity to traffic. In multivariate models, annoyance from air pollution was related to NO2, building age, and country of birth; annoyance from noise was only related to the first two. The health burden of these exposures can be increased by stress caused by the perception of pollution sources. PMID:26095869

  4. Airport noise

    NASA Technical Reports Server (NTRS)

    Pendley, R. E.

    1982-01-01

    The problem of airport noise at several airports and air bases is detailed. Community reactions to the noise, steps taken to reduce jet engine noise, and the effect of airport use restrictions and curfews on air transportation are discussed. The adverse effect of changes in allowable operational noise on airport safety and altenative means for reducing noise pollution are considered. Community-airport relations and public relations are discussed.

  5. Guns and Violence. Current Controversies.

    ERIC Educational Resources Information Center

    Kim, Henny H., Ed.

    This book focuses on gun violence and gun control, presenting both sides of arguments about firearms ownership and gun control. Each of five chapters poses a question about gun control and provides answers for both sides of the question. The following essays are included: (1) "Gun Violence Is Becoming an Epidemic" (Bob Herbert); (2) "Gun Violence…

  6. Gun Safety (For Kids)

    MedlinePlus

    ... guns are featured in many television shows, video games, computer games, and movies, it's important to know that real ... only happen on TV, in movies, or video games. A real gun is never a toy, and ...

  7. A study of the prediction of cruise noise and laminar flow control noise criteria for subsonic air transports

    NASA Technical Reports Server (NTRS)

    Swift, G.; Mungur, P.

    1979-01-01

    General procedures for the prediction of component noise levels incident upon airframe surfaces during cruise are developed. Contributing noise sources are those associated with the propulsion system, the airframe and the laminar flow control (LFC) system. Transformation procedures from the best prediction base of each noise source to the transonic cruise condition are established. Two approaches to LFC/acoustic criteria are developed. The first is a semi-empirical extension of the X-21 LFC/acoustic criteria to include sensitivity to the spectrum and directionality of the sound field. In the second, the more fundamental problem of how sound excites boundary layer disturbances is analyzed by deriving and solving an inhomogeneous Orr-Sommerfeld equation in which the source terms are proportional to the production and dissipation of sound induced fluctuating vorticity. Numerical solutions are obtained and compared with corresponding measurements. Recommendations are made to improve and validate both the cruise noise prediction methods and the LFC/acoustic criteria.

  8. Associations between Traffic Noise, Particulate Air Pollution, Hypertension, and Isolated Systolic Hypertension in Adults: The KORA Study

    PubMed Central

    Wolf, Kathrin; Petz, Markus; Heinrich, Joachim; Cyrys, Josef; Peters, Annette

    2014-01-01

    Background: Studies on the association between traffic noise and cardiovascular diseases have rarely considered air pollution as a covariate in the analyses. Isolated systolic hypertension has not yet been in the focus of epidemiological noise research. Methods: The association between traffic noise (road and rail) and the prevalence of hypertension was assessed in two study populations with a total of 4,166 participants 25–74 years of age. Traffic noise (weighted day–night average noise level; LDN) at the facade of the dwellings was derived from noise maps. Annual average PM2.5 mass concentrations at residential addresses were estimated by land-use regression. Hypertension was assessed by blood pressure readings, self-reported doctor-diagnosed hypertension, and antihypertensive drug intake. Results: In the Greater Augsburg, Germany, study population, traffic noise and air pollution were not associated with hypertension. In the City of Augsburg population (n = 1,893), where the exposure assessment was more detailed, the adjusted odds ratio (OR) for a 10-dB(A) increase in noise was 1.16 (95% CI: 1.00, 1.35), and 1.11 (95% CI: 0.94, 1.30) after additional adjustment for PM2.5. The adjusted OR for a 1-μg/m3 increase in PM2.5 was 1.15 (95% CI: 1.02, 1.30), and 1.11 (95% CI: 0.98, 1.27) after additional adjustment for noise. For isolated systolic hypertension, the fully adjusted OR for noise was 1.43 (95% CI: 1.10, 1.86) and for PM2.5 was 1.08 (95% CI: 0.87, 1.34). Conclusions: Traffic noise and PM2.5 were both associated with a higher prevalence of hypertension. Mutually adjusted associations with hypertension were positive but no longer statistically significant. Citation: Babisch W, Wolf K, Petz M, Heinrich J, Cyrys J, Peters A. 2014. Associations between traffic noise, particulate air pollution, hypertension, and isolated systolic hypertension in adults: the KORA Study. Environ Health Perspect 122:492–498; http://dx.doi.org/10.1289/ehp.1306981 PMID:24602804

  9. Environmental Resources of Selected Areas of Hawaii: Climate, Ambient Air Quality, and Noise (DRAFT)

    SciTech Connect

    Lombardi, D.A.; Blasing, T.J.; Easterly, C.E.; Hamilton, C.B.

    1994-06-01

    This report has been prepared to make available and archive background scientific data and related information on climate, ambient air quality, and ambient noise levels collected during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of hawaii in its April 1989 proposal to Congress. The US Department of Energy (DOE) published a notice in the Federal Register on May 17, 1994 withdrawing its Notice of Intent of February 14, 1992, to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The report presents a general description of the climate and air quality for the islands of Hawaii (henceforth referred to as Hawaii), Maui, and Oahu. It also presents a literature review as baseline information on the health effects of hydrogen sulfide. the scientific background data and related information is being made available for use by others in conducting future scientific research in these areas. This report describes the environmental resources present in the areas studied (i.e., the affected environment) and does not represent an assessment of environmental impacts.

  10. Environmental resources of selected areas of Hawaii: Climate, ambient air quality, and noise

    SciTech Connect

    Lombardi, D.A.; Blasing, T.J.; Easterly, C.E.; Reed, R.M.; Hamilton, C.B.

    1995-03-01

    This report has been prepared to make available and archive background scientific data and related information on climate, ambient air quality, and ambient noise levels collected during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. The US Department of Energy (DOE) published a notice withdrawing its Notice of Intent to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The report presents a general description of the climate add air quality for the islands of Hawaii (henceforth referred to as Hawaii), Maui and Oahu. It also presents a literature review as baseline information on the health effects of sulfide. The scientific background data and related information is being made available for use by others in conducting future scientific research in these areas. This report describes the environmental resources present in the areas studied (i.e., the affected environment) and does not represent an assessment of environmental impacts.

  11. 32 CFR 256.10 - Air installations compatible use zone noise descriptors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... noise contours and these noise contours shall be plotted on maps accompanying AICUZ studies. (c) Where... used, data shall be collected sufficient to permit computation of Ldn 75 noise contours and these noise contours shall be plotted on maps accompanying AICUZ studies. (d) Where previous studies have used CNR...

  12. Energy and Environment 1990: Transportation-induced noise and air pollution

    SciTech Connect

    Not Available

    1990-01-01

    Contents: public reaction to low levels of aircraft noise; airport noise insulation of homes surrounding stapleton international airport; sound insulation and thermal performance modifications: case study for three dwellings near bwi airport; single-number ratings for outdoor-indoor sound insulation; control of wheel squeal noise in rail transit cars; knowledge-based preprocessor for traffic noise prediction; barrier overlap analysis procedure; atmospheric effects on traffic noise propagation; predicting stop-and-go traffic noise with stamina 2.0; feasibility of transparent noise barriers; field testing of the effectiveness of open-graded asphalt pavement in reducing tire noise from highway vehicles; cost of noise barrier construction in the united states; comparisons of emissions of transit buses using methanol and diesel fuel; high-speed rail system noise assessment; energy-related, environmental, and economic benefits of florida's high-speed rail and maglev systems proposals.

  13. Survey of SRF guns

    SciTech Connect

    Belomestnykh, S.

    2011-07-25

    Developing Superconducting RF (SRF) electron guns is an active field with several laboratories working on different gun designs. While the first guns were based on elliptic cavity geometries, Quarter Wave Resonator (QWR) option is gaining popularity. QWRs are especially well suited for producing beams with high charge per bunch. In this talk we will describe recent progress in developing both types of SRF guns. SRF guns made excellent progress in the last two years. Several guns generated beams and one, at HZDR, injected beam into an accelerator. By accomplishing this, HZDR/ELBE gun demonstrated feasibility of the SRF gun concept with a normal-conducting Cs{sub 2}Te cathode. The cathode demonstrated very good performance with the lifetime of {approx}1 year. However, for high average current/high bunch charge operation CsK{sub 2}Sb is preferred as it needs green lasers, unlike UV laser for the Cs{sub 2}Te, which makes it easier to build laser/optics systems. Other high QE photocathodes are being developed for SRF guns, most notably diamond-amplified photocathode. Several QWR guns are under development with one producing beam already. They are very promising for high bunch charge operation. The field is very active and we should expect more good results soon.

  14. Evaluation of the effects of exposure to organic solvents and hazardous noise among US Air Force Reserve personnel.

    PubMed

    Hughes, Hayley; Hunting, Katherine L

    2013-01-01

    Hearing loss affects many workers including those in the military and may be caused by noise, medications, and chemicals. Exposures to some chemicals may lead to an increase in the incidence of hearing loss when combined with hazardous noise. This retrospective study evaluated the risk for hearing loss among Air Force Reserve personnel exposed to occupational noise with and without exposures to toluene, styrene, xylene, benzene, and JP-8 (jet fuel). Risk factors associated with hearing loss were determined using logistic and linear regression. Stratified analysis was used to evaluate potential interaction between solvent and noise exposure. The majority of the subjects were male (94.6%) and 35 years or older on the date of their first study audiogram (66%). Followed for an average of 3.2 years, 9.2% of the study subjects had hearing loss in at least one ear. Increasing age (odds ratio [OR] = 1.03 per year of age) and each year of follow-up time (OR = 1.23) were significantly associated with hearing loss. Low and moderate solvent exposures were not associated with hearing loss. Linear regression demonstrated that hearing loss was significantly associated with age at first study audiogram, length of follow-up time, and exposure to noise. Hearing decreased by 0.04 decibels for every decibel increase in noise level or by almost half a decibel (0.4 dB) for every 10 decibel increase in noise level. PMID:24231416

  15. Overweight, air and noise pollution: Universal risk factors for pediatric pre-hypertension

    PubMed Central

    Kelishadi, Roya; Poursafa, Parinaz; Keramatian, Kasra

    2011-01-01

    Pediatric pre-hypertension (pre-HTN) has a complex multifactorial etiology. Although most cases are secondary to other disorders, a substantial number of children and adolescents have primary or essential HTN and pre-HTN. The gene-gene and gene-environment interactions should be considered in this context. The strong relationship of pre-HTN with environmental factors such as air pollution, noise pollution and passive smoking and obesity suggest that its prevalence will be escalating. Exposure to ambient particulate matters may increase blood pressure (BP) within hours to days. The underlying biologic pathways include autonomic nervous system imbalance and arterial vascular dysfunction or vasoconstriction because of systemic oxidative stress and inflammation. Likewise, tobacco smoke exposure of pregnant mothers increases systolic BP of their offspring in early infancy. Parental smoking also independently affects systolic BP among healthy preschool children. Noise exposure, notably in night, is associated with catecholamine secretion, increased BP and a pre-HTN state even in pre-school age children. Excess weight is associated with dysfunction of the adipose tissue, consisting of enlarged hypertrophied adipocytes, increased infiltration by macrophages and variations in secretion of adipokines and free fatty acids. These changes would result in chronic vascular inflammation, oxidative stress, activation of the renin-angiotensin-aldosterone system and sympathetic response, and ultimately to pre-HTN from childhood. Prevention and control of the modifiable risk factors of pre-HTN from prenatal period can have long-term health impact on primordial and primary prevention of chronic non-communicable diseases. This review presents a general view on the diagnosis, prevalence and etiology of pre-HTN along with practical measures for its prevention and control. PMID:22973395

  16. Women and Guns. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Many gun manufacturers market guns to women claiming a gun can provide protection. Statistics provided in this fact sheet indicate gun ownership may provide a false sense of security that can be fatal, since the greatest threat to a woman comes from the people and guns within her own home. Contrary to "typical" scenarios created by advertisers,…

  17. Borehole-explosion and air-gun data acquired in the 2011 Salton Seismic Imaging Project (SSIP), southern California: description of the survey

    USGS Publications Warehouse

    Rose, Elizabeth J.; Fuis, Gary S.; Stock, Joann M.; Hole, John A.; Kell, Annie M.; Kent, Graham; Driscoll, Neal W.; Goldman, Mark; Reusch, Angela M.; Han, Liang; Sickler, Robert R.; Catchings, Rufus D.; Rymer, Michael J.; Criley, Coyn J.; Scheirer, Daniel S.; Skinner, Steven M.; Slayday-Criley, Coye J.; Murphy, Janice M.; Jensen, Edward G.; McClearn, Robert; Ferguson, Alex J.; Butcher, Lesley A.; Gardner, Max A.; Emmons, Iain; Loughran, Caleb L.; Svitek, Joseph R.; Bastien, Patrick C.; Cotton, Joseph A.; Croker, David S.; Harding, Alistair J.; Babcock, Jeffrey M.; Harder, Steven H.; Rosa, Carla M.

    2013-01-01

    detailed images we need for earthquake hazard assessment. Air gun bursts, generated in the Salton Sea along extensions of our onshore seismic lines, also were utilized as sound-wave sources. Temporary deployments of portable land seismometers, as well as ocean-bottom seismometers (OBSs) on the floor of the Salton Sea, recorded the energy from the land shots and air gun bursts. SSIP is similar to the Los Angeles Regional Seismic Experiments of 1994 and 1999 (LARSE I and II, respectively; Murphy and others, 1996; Fuis and others, 2001). The LARSE surveys demonstrated that the USGS and collaborators can safely and effectively conduct seismic imaging surveys in urban and nonurban areas, on lands owned and/or managed by many different types of agencies and entities. Information was produced that could not have been obtained any other way, and this information was key to changing the leading ideas about earthquake hazards at that time in the Los Angeles region. These surveys produced no significant environmental impact or damage to structures, and they did not trigger earthquakes.

  18. Interior of southeast gun chamber (labeled "Gun Turret No. Two), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior of southeast gun chamber (labeled "Gun Turret No. Two), showing gun mounting pad, wall rings, small niche, and opening to outside - U.S. Naval Base, Pearl Harbor, Battery Adair, Princeton Place, Pearl City, Honolulu County, HI

  19. Carbon Nanotube Electron Gun

    NASA Technical Reports Server (NTRS)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

    2013-01-01

    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  20. Carbon nanotube electron gun

    NASA Technical Reports Server (NTRS)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

    2010-01-01

    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  1. FEATURE 3, LARGE GUN POSITION, ARMCO HUT (FEATURE 4) IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 3, LARGE GUN POSITION, ARMCO HUT (FEATURE 4) IN BACKGROUND, VIEW FACING NORTH. - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Large Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  2. 14. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), LOOKING EAST AT SOUTHWEST END OF BUILDING. HVAC EQUIPMENT LOCATED OUTDOORS IN FOREGROUND. DUCTS CONDUCT HOT OR COLD AIR INDOORS. ROUND PIPES ARE INSULATED STEAM LINES. BUILDING NO. 448, ORDNANCE FACILITY, IN BACKGROUND. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  3. FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING SOUTH (with scale stick). - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Large Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  4. Moderate variations of mood/emotional states related to alterations in cochlear otoacoustic emissions and tinnitus onset in young normal hearing subjects exposed to gun impulse noise.

    PubMed

    Job, Agnès; Cian, Corinne; Esquivié, Dominique; Leifflen, Daniel; Trousselard, Marion; Charles, Corinne; Nottet, Jean-Bertrand

    2004-07-01

    This study was designed to test whether under impulse noise exposure mood and emotional states could play a role in the onset of tinnitus and/or could modify cochlear sensitivity objectively measured with distortion product otoacoustic emissions (DPOAEs). The experimental design consisted in a short follow-up study of 54 young military subjects (20+/-2 years old), psychologically normal, with normal hearing, during two consecutive days of target practice rounds. Data collection included an abbreviated version of the profile of mood states (POMSs) inventory [Profile of Mood States, Educational and Industrial Testing Service, San Diego, 1971], questionnaires on tinnitus perception (previous history and after shooting) and DPOAEs measurements before and after shooting. Higher scores of tension-anxiety were found in subjects having previous history of tinnitus. Association between tinnitus previous history and tinnitus after shooting was found significant. Perception of tinnitus after target practice rounds was associated with significantly lower DPOAEs at 3 kHz. The most tense-anxious subjects were found to have DPOAEs decreases of 3.35+/-6 dB at 3 kHz after shooting. This study clearly shows that, in young healthy population, psychologically normal and with normal hearing, moderate variations in mood and emotional states were related to tinnitus onset and DPOAEs alterations. It is possible that stronger variations in mood and/or emotional condition would increase risks of tinnitus and alterations of cochlear sensitivity. PMID:15219318

  5. Noise emitted from road, rail and air traffic and their effects on sleep

    NASA Astrophysics Data System (ADS)

    Griefahn, Barbara; Marks, Anke; Robens, Sibylle

    2006-08-01

    This study compared the effects of road, rail, and aircraft noise and tested the applicability of the equivalent noise level for the evaluation of sleep disturbances. Sixteen women and 16 men (19-28 years) slept during 3 consecutive weeks in the laboratory. Eight persons slept in quiet throughout. Twenty-four persons were exposed to road, rail, or aircraft noise with weekly permuted changes. Each week consisted of a random sequence of a quiet night (32 dBA) and 3 nights with equivalent noise levels of 39, 44, and 50 dBA and maximum levels of 50-62, 56-68, and 62-74 dBA, respectively. The polysomnogram was recorded during all nights, sleep quality was assessed and performance tests were completed in the morning. Subjectively evaluated sleep quality decreased and reaction time increased gradually with noise levels, whereas most physiological variables revealed the same reactions to both the lower and considerably stronger reactions to the highest noise load. Aircraft noise, rail and road traffic noise caused similar after-effects but physiological sleep parameters were most severely affected by rail noise. The equivalent noise level seems to be a suitable predictor for subjectively evaluated sleep quality but not for physiological sleep disturbances.

  6. Remotely controlled spray gun

    NASA Technical Reports Server (NTRS)

    Cunningham, William C. (Inventor)

    1987-01-01

    A remotely controlled spray gun is described in which a nozzle and orifice plate are held in precise axial alignment by an alignment member, which in turn is held in alignment with the general outlet of the spray gun by insert. By this arrangement, the precise repeatability of spray patterns is insured.

  7. Modeling internal ballistics of gas combustion guns.

    PubMed

    Schorge, Volker; Grossjohann, Rico; Schönekess, Holger C; Herbst, Jörg; Bockholdt, Britta; Ekkernkamp, Axel; Frank, Matthias

    2016-05-01

    Potato guns are popular homemade guns which work on the principle of gas combustion. They are usually constructed for recreational rather than criminal purposes. Yet some serious injuries and fatalities due to these guns are reported. As information on the internal ballistics of homemade gas combustion-powered guns is scarce, it is the aim of this work to provide an experimental model of the internal ballistics of these devices and to investigate their basic physical parameters. A gas combustion gun was constructed with a steel tube as the main component. Gas/air mixtures of acetylene, hydrogen, and ethylene were used as propellants for discharging a 46-mm caliber test projectile. Gas pressure in the combustion chamber was captured with a piezoelectric pressure sensor. Projectile velocity was measured with a ballistic speed measurement system. The maximum gas pressure, the maximum rate of pressure rise, the time parameters of the pressure curve, and the velocity and path of the projectile through the barrel as a function of time were determined according to the pressure-time curve. The maximum gas pressure was measured to be between 1.4 bar (ethylene) and 4.5 bar (acetylene). The highest maximum rate of pressure rise was determined for hydrogen at (dp/dt)max = 607 bar/s. The muzzle energy was calculated to be between 67 J (ethylene) and 204 J (acetylene). To conclude, this work provides basic information on the internal ballistics of homemade gas combustion guns. The risk of injury to the operator or bystanders is high, because accidental explosions of the gun due to the high-pressure rise during combustion of the gas/air mixture may occur. PMID:26239103

  8. Miniature paint-spray gun for recessed areas

    NASA Technical Reports Server (NTRS)

    Vanasse, M. A.

    1968-01-01

    Miniature spray gun regulates paints and other liquids to spray at close range, facilitating spraying of remote or recessed areas. Individual valves for regulating air pressure and paint maximizes atomization for low pressure spraying.

  9. Addressing Challenges in Studies of Behavioral Responses of Whales to Noise.

    PubMed

    Cato, Douglas H; Dunlop, Rebecca A; Noad, Michael J; McCauley, Robert D; Kniest, Eric; Paton, David; Kavanagh, Ailbhe S

    2016-01-01

    Studying the behavioral response of whales to noise presents numerous challenges. In addition to the characteristics of the noise exposure, many factors may affect the response and these must be measured and accounted for in the analysis. An adequate sample size that includes matching controls is crucial if meaningful results are to be obtained. Field work is thus complicated, logistically difficult, and expensive. This paper discusses some of the challenges and how they are being met in a large-scale multiplatform project in which humpback whales are exposed to the noise of seismic air guns. PMID:26610954

  10. Rarefaction wave gun propulsion

    NASA Astrophysics Data System (ADS)

    Kathe, Eric Lee

    A new species of gun propulsion that dramatically reduces recoil momentum imparted to the gun is presented. First conceived by the author on 18 March 1999, the propulsion concept is explained, a methodology for the design of a reasonable apparatus for experimental validation using NATO standard 35mm TP anti-aircraft ammunition is developed, and the experimental results are presented. The firing results are juxtaposed by a simple interior ballistic model to place the experimental findings into a context within which they may better be understood. Rarefaction wave gun (RAVEN) propulsion is an original contribution to the field of armament engineering. No precedent is known, and no experimental results of such a gun have been published until now. Recoil reduction in excess of 50% was experimentally achieved without measured loss in projectile velocity. RAVEN achieves recoil reduction by means of a delayed venting of the breech of the gun chamber that directs the high enthalpy propellant gases through an expansion nozzle to generate forward thrust that abates the rearward momentum applied to the gun prior to venting. The novel feature of RAVEN, relative to prior recoilless rifles, is that sufficiently delayed venting results in a rarefaction wave that follows the projectile though the bore without catching it. Thus, the projectile exits the muzzle without any compromise to its propulsion performance relative to guns that maintain a sealed chamber.

  11. Traffic-Related Air Pollution, Noise at School, and Behavioral Problems in Barcelona Schoolchildren: A Cross-Sectional Study

    PubMed Central

    Forns, Joan; Dadvand, Payam; Foraster, Maria; Alvarez-Pedrerol, Mar; Rivas, Ioar; López-Vicente, Mònica; Suades-Gonzalez, Elisabet; Garcia-Esteban, Raquel; Esnaola, Mikel; Cirach, Marta; Grellier, James; Basagaña, Xavier; Querol, Xavier; Guxens, Mònica; Nieuwenhuijsen, Mark J.; Sunyer, Jordi

    2015-01-01

    Background: The available evidence of the effects of air pollution and noise on behavioral development is limited, and it overlooks exposure at schools, where children spend a considerable amount of time. Objective: We aimed to investigate the associations of exposure to traffic-related air pollutants (TRAPs) and noise at school on behavioral development of schoolchildren. Methods: We evaluated children 7–11 years of age in Barcelona (Catalonia, Spain) during 2012–2013 within the BREATHE project. Indoor and outdoor concentrations of elemental carbon (EC), black carbon (BC), and nitrogen dioxide (NO2) were measured at schools in two separate 1-week campaigns. In one campaign we also measured noise levels inside classrooms. Parents filled out the strengths and difficulties questionnaire (SDQ) to assess child behavioral development, while teachers completed the attention deficit/hyperactivity disorder criteria of the DSM-IV (ADHD-DSM-IV) list to assess specific ADHD symptomatology. Negative binomial mixed-effects models were used to estimate associations between the exposures and behavioral development scores. Results: Interquartile range (IQR) increases in indoor and outdoor EC, BC, and NO2 concentrations were positively associated with SDQ total difficulties scores (suggesting more frequent behavioral problems) in adjusted multivariate models, whereas noise was significantly associated with ADHD-DSM-IV scores. Conclusion: In our study population of 7- to 11-year-old children residing in Barcelona, exposure to TRAPs at school was associated with increased behavioral problems in schoolchildren. Noise exposure at school was associated with more ADHD symptoms. Citation: Forns J, Dadvand P, Foraster M, Alvarez-Pedrerol M, Rivas I, López-Vicente M, Suades-Gonzalez E, Garcia-Esteban R, Esnaola M, Cirach M, Grellier J, Basagaña X, Querol X, Guxens M, Nieuwenhuijsen MJ, Sunyer J. 2016. Traffic-related air pollution, noise at school, and behavioral problems in Barcelona

  12. Locating air leaks in manned spacecraft using structure-borne noise.

    PubMed

    Holland, Stephen D; Chimenti, D E; Roberts, Ron; Strei, Michael

    2007-06-01

    All manned spacecraft are vulnerable to leaks generated by micrometeorite or debris impacts. Methods for locating such leaks using leak-generated, structure-borne ultrasonic noise are discussed and demonstrated. Cross-correlations of ultrasonic noise waveforms from a leak into vacuum are used to find the location of the leak. Four methods for sensing and processing leak noise have been developed and tested and each of these can be used to reveal the leak location. The methods, based on phased-array, distributed sensor, and dual sensor approaches, utilize the propagation patterns of guided ultrasonic Lamb waves in the spacecraft skin structure to find the source or direction of the leak noise. It is shown that each method can be used to successfully locate the leak to within a few millimeters on a 0.6-m2 aluminum plate. The relative merits of the four methods are discussed. PMID:17552700

  13. Influence of Solid Noise Barriers on Near-Road and On-Road Air Quality

    EPA Science Inventory

    Public health concerns regarding adverse health effects for populations spending significant amounts of time near high traffic roadways has increased substantially in recent years. Roadside features, including solid noise barriers, have been investigated as potential methods to ...

  14. Comparison of a laboratory and a production coating spray gun with respect to scale-up.

    PubMed

    Mueller, Ronny; Kleinebudde, Peter

    2007-01-01

    A laboratory spray gun and a production spray gun were investigated in a scale-up study. Two Schlick spray guns, which are equipped with a new antibearding cap, were used in this study. The influence of the atomization air pressure, spray gun-to tablet bed distance, polymer solution viscosity, and spray rate were analyzed in a statistical design of experiments. The 2 spray guns were compared with respect to the spray width and height, droplet size, droplet velocity, and spray density. The droplet size, velocity, and spray density were measured with a Phase Doppler Particle Analyzer. A successful scale-up of the atomization is accomplished if similar droplet sizes, droplet velocities, and spray densities are achieved in the production scale as in the laboratory scale. This study gives basic information for the scale-up of the settings from the laboratory spray gun to the production spray gun. Both spray guns are highly comparable with respect to the droplet size and velocity. The scale-up of the droplet size should be performed by an adjustment of the atomization air pressure. The scale-up of the droplet velocity should be performed by an adjustment of the spray gun to tablet bed distance. The presented statistical model and surface plots are convenient and powerful tools for scaling up the spray settings if the spray gun is changed from laboratory spray gun to the production spray gun. PMID:17408226

  15. Behavioral responses of gray whales to industrial noise: feeding observations and predictive modeling

    SciTech Connect

    Malme, C.I.; Wuersig, B.; Bird, J.E.; Tyack, P.

    1986-08-01

    An investigation was made of the potential effects of underwater noise from petroleum-industry activities on feeding gray whales. The investigation consisted of two components, a field study and an acoustic model study. The field study was performed near Southeast Cape, St. Lawrence Island in August, 1985, using a 100 cu. in. air gun source and playback of drillship noise. Sound-source levels and acoustic-propagation losses were measured to permit estimation of sound exposure levels at whale-sighting positions. For the air-gun source there was a 0.5 probability that the whales would stop feeding and move away from the area when the average pulse levels reached 173 dB.

  16. RF Gun Optimization Study

    SciTech Connect

    A. S. Hofler; P. Evtushenko; M. Krasilnikov

    2007-08-01

    Injector gun design is an iterative process where the designer optimizes a few nonlinearly interdependent beam parameters to achieve the required beam quality for a particle accelerator. Few tools exist to automate the optimization process and thoroughly explore the parameter space. The challenging beam requirements of new accelerator applications such as light sources and electron cooling devices drive the development of RF and SRF photo injectors. RF and SRF gun design is further complicated because the bunches are space charge dominated and require additional emittance compensation. A genetic algorithm has been successfully used to optimize DC photo injector designs for Cornell* and Jefferson Lab**, and we propose studying how the genetic algorithm techniques can be applied to the design of RF and SRF gun injectors. In this paper, we report on the initial phase of the study where we model and optimize gun designs that have been benchmarked with beam measurements and simulation.

  17. High Velocity Gas Gun

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A video tape related to orbital debris research is presented. The video tape covers the process of loading a High Velocity Gas Gun and firing it into a mounted metal plate. The process is then repeated in slow motion.

  18. Aircraft noise problems

    NASA Astrophysics Data System (ADS)

    1981-01-01

    The problems related to aircraft noise were studied. Physical origin (sound), human reaction (noise), quantization of noise and sound sources of aircraft noise are discussed. Noise abatement at the source, technical, fleet-political and air traffic measures are explained. The measurements and future developments are also discussed. The position of Lufthansa as regards aircraft noise problems is depicted.

  19. High Blood Pressure and Long-Term Exposure to Indoor Noise and Air Pollution from Road Traffic

    PubMed Central

    Künzli, Nino; Aguilera, Inmaculada; Rivera, Marcela; Agis, David; Vila, Joan; Bouso, Laura; Deltell, Alexandre; Marrugat, Jaume; Ramos, Rafel; Sunyer, Jordi; Elosua, Roberto; Basagaña, Xavier

    2014-01-01

    Background: Traffic noise has been associated with prevalence of hypertension, but reports are inconsistent for blood pressure (BP). To ascertain noise effects and to disentangle them from those suspected to be from traffic-related air pollution, it may be essential to estimate people’s noise exposure indoors in bedrooms. Objectives: We analyzed associations between long-term exposure to indoor traffic noise in bedrooms and prevalent hypertension and systolic (SBP) and diastolic (DBP) BP, considering long-term exposure to outdoor nitrogen dioxide (NO2). Methods: We evaluated 1,926 cohort participants at baseline (years 2003–2006; Girona, Spain). Outdoor annual average levels of nighttime traffic noise (Lnight) and NO2 were estimated at postal addresses with a detailed traffic noise model and a land-use regression model, respectively. Individual indoor traffic Lnight levels were derived from outdoor Lnight with application of insulations provided by reported noise-reducing factors. We assessed associations for hypertension and BP with multi-exposure logistic and linear regression models, respectively. Results: Median levels were 27.1 dB(A) (indoor Lnight), 56.7 dB(A) (outdoor Lnight), and 26.8 μg/m3 (NO2). Spearman correlations between outdoor and indoor Lnight with NO2 were 0.75 and 0.23, respectively. Indoor Lnight was associated both with hypertension (OR = 1.06; 95% CI: 0.99, 1.13) and SBP (β = 0.72; 95% CI: 0.29, 1.15) per 5 dB(A); and NO2 was associated with hypertension (OR = 1.16; 95% CI: 0.99, 1.36), SBP (β = 1.23; 95% CI: 0.21, 2.25), and DBP (β⊇= 0.56; 95% CI: –0.03, 1.14) per 10 μg/m3. In the outdoor noise model, Lnight was associated only with hypertension and NO2 with BP only. The indoor noise–SBP association was stronger and statistically significant with a threshold at 30 dB(A). Conclusion: Long-term exposure to indoor traffic noise was associated with prevalent hypertension and SBP, independently of NO2. Associations were less

  20. Numerical simulation of tonal fan noise of computers and air conditioning systems

    NASA Astrophysics Data System (ADS)

    Aksenov, A. A.; Gavrilyuk, V. N.; Timushev, S. F.

    2016-07-01

    Current approaches to fan noise simulation are mainly based on the Lighthill equation and socalled aeroacoustic analogy, which are also based on the transformed Lighthill equation, such as the wellknown FW-H equation or the Kirchhoff theorem. A disadvantage of such methods leading to significant modeling errors is associated with incorrect solution of the decomposition problem, i.e., separation of acoustic and vortex (pseudosound) modes in the area of the oscillation source. In this paper, we propose a method for tonal noise simulation based on the mesh solution of the Helmholtz equation for the Fourier transform of pressure perturbation with boundary conditions in the form of the complex impedance. A noise source is placed on the surface surrounding each fan rotor. The acoustic fan power is determined by the acoustic-vortex method, which ensures more accurate decomposition and determination of the pressure pulsation amplitudes in the near field of the fan.

  1. The influence of tree stands and a noise barrier on near-roadway air quality

    EPA Science Inventory

    Prediction of air pollution exposure levels of people living near or commuting on roadways is still very problematic due to the highly localized nature of traffic intensity, fleet composition, and extremely complex air flow patterns in urban areas. Both modelling and field studie...

  2. Exposures to road traffic, noise, and air pollution as risk factors for type 2 diabetes: A feasibility study in Bulgaria.

    PubMed

    Dzhambov, Angel M; Dimitrova, Donka D

    2016-01-01

    Type 2 diabetes mellitus (T2DM) is a growing public health problem in Bulgaria. While individual and lifestyle determinants have been researched; till date there has been no study on environmental risks such as road traffic, noise, and air pollution. As a first step toward designing a large-scale population-based survey, we aimed at exploring the overall associations of prevalent T2DM with exposures to road traffic, noise, and air pollution. A total of 513 residents of Plovdiv city, Bulgaria were recruited. Individual data on self-reported doctor-diagnosed T2DM and confounding factors were linked to objective and self-rated exposure indicators. Logistic and log-link Poisson regressions were conducted. In the fully adjusted logistic models, T2DM was positively associated with exposures to L(den) 71-80 dB (odds ratio (OR) = 4.49, 95% confidence interval (CI): 1.38, 14.68), fine particulate matter (PM) 2.5 25.0-66.8 μg/m 3 (OR = 1.32, 95% CI: 0.28, 6.24), benzo alpha pyrene 6.0-14.02 ng/m 3 (OR = 1.76, 95% CI: 0.52, 5.98) and high road traffic (OR = 1.40, 95% CI: 0.48, 4.07). L(den) remained a significant risk factor in the: Poisson regression model. Other covariates with consistently high multivariate effects were age, gender, body mass index, family history of T2DM, subjective sleep disturbance, and especially bedroom location. We concluded that residential noise exposure might be associated with elevated risk of prevalent T2DM. The inferences made by this research and the lessons learned from its limitations could guide the designing of a longitudinal epidemiological survey in Bulgaria. PMID:27157686

  3. Exposures to road traffic, noise, and air pollution as risk factors for type 2 diabetes: A feasibility study in Bulgaria

    PubMed Central

    Dzhambov, Angel M; Dimitrova, Donka D

    2016-01-01

    Type 2 diabetes mellitus (T2DM) is a growing public health problem in Bulgaria. While individual and lifestyle determinants have been researched; till date there has been no study on environmental risks such as road traffic, noise, and air pollution. As a first step toward designing a large-scale population-based survey, we aimed at exploring the overall associations of prevalent T2DM with exposures to road traffic, noise, and air pollution. A total of 513 residents of Plovdiv city, Bulgaria were recruited. Individual data on self-reported doctor-diagnosed T2DM and confounding factors were linked to objective and self-rated exposure indicators. Logistic and log-link Poisson regressions were conducted. In the fully adjusted logistic models, T2DM was positively associated with exposures to Lden 71-80 dB (odds ratio (OR) = 4.49, 95% confidence interval (CI): 1.38, 14.68), fine particulate matter (PM)2.5 25.0-66.8 μg/m3 (OR = 1.32, 95% CI: 0.28, 6.24), benzo alpha pyrene 6.0-14.02 ng/m3 (OR = 1.76, 95% CI: 0.52, 5.98) and high road traffic (OR = 1.40, 95% CI: 0.48, 4.07). Lden remained a significant risk factor in the: Poisson regression model. Other covariates with consistently high multivariate effects were age, gender, body mass index, family history of T2DM, subjective sleep disturbance, and especially bedroom location. We concluded that residential noise exposure might be associated with elevated risk of prevalent T2DM. The inferences made by this research and the lessons learned from its limitations could guide the designing of a longitudinal epidemiological survey in Bulgaria. PMID:27157686

  4. Electromagnetic targeting of guns

    SciTech Connect

    Pogue, E.W.; Boat, R.M.; Holden, D.N.; Lopez, J.R.

    1996-10-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Electromagnetic pulse (EMP) signals produced from explosives being fired have been reported in the literature for fifty years. When a gun is fired it produces an EMP muzzle blast signal. The strength and nature of these signals was first analyzed in the early 1970s, while the results were interesting, no follow-up studies were conducted. With modern detection and signal processing technology, we believe that these signals could be used to instantaneously locate guns of virtually all calibers as they fire. The objective of our one-year project was to establish the basic nature of these signals and their utility in the concept of electromagnetic targeting of guns.

  5. Mole gun injury.

    PubMed

    Pistré, V; Rezzouk, J

    2013-09-01

    A mole gun is a weapon, which is used to trap and kill moles. This report provides an overview of the state of knowledge of mole gun injuries, comparable to blast injuries caused by fireworks, explosive or gunshot. Over a 2-year period, the authors reported their experience with ten hand injuries caused by mole gun. Radial side of the hand was often concerned, particularly the thumb. The authors explain their choices in the management of such lesions. Surgery was performed primarily and a large debridement currently seemed to offer the best outcome for the patient. Blast, crush, burns and lacerations may explain the higher rate of amputation to the digits. A long period of physiotherapy, specifically of the hand, was needed before the patient could return to work. This ballistic hand trauma encountered by surgeons requires knowledge and understanding of these injuries. It should be in accordance with firearms law because of severe injuries encountered and possible lethal wounds. PMID:23746826

  6. 32 CFR 256.10 - Air installations compatible use zone noise descriptors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Forecast (NEF) values as previously required by Sections III., IV., and V. of DoD Instruction 4165.57, “Air... available in the Office of the Assistant Secretary of Defense (Installations and Logistics)—IO,...

  7. THE INFLUENCE OF A NOISE BARRIER AND VEGETATION ON AIR QUALITY NEAR A ROADWAY

    EPA Science Inventory

    A growing number of epidemiological studies conducted throughout the world have identified an increase in occurrence of adverse health effects for populations residing, working or attending school near major roadways. In addition, several air quality studies have identified incr...

  8. Where the guns come from: the gun industry and gun commerce.

    PubMed

    Wintemute, Garen J

    2002-01-01

    Under federal law, it is illegal for youth under age 18 to purchase rifles or shotguns, and for those under age 21 to purchase handguns. However, fatality and injury statistics clearly show that guns are finding their way into young people's hands. Many of these youth obtain guns through illegal gun markets. This article focuses on how guns in the United States are manufactured, marketed, and sold. The article shows how the legal and illegal gun markets are intimately connected and make guns easily accessible to youth. Although the domestic gun manufacturing industry is relatively small and has experienced declining sales in recent years, it has significant political clout and a large market for its products, and has engaged in aggressive marketing to youth. Lax oversight of licensed firearms dealers, combined with little or no regulation of private sales between gun owners, mean that guns can quickly moved from the legal gun market into the illegal market, where they can be acquired by young people. Certain guns, especially inexpensive, poorly made small handguns, are particularly attractive to criminals and youth. The author observes that several policy innovations--including increased regulation of licensed firearms dealers, intensified screening of prospective buyers, regulation of private sales, gun licensing and registration, and bans on some types of weapons--hold promise for decreasing the flow of guns into the hands of youth. PMID:12194613

  9. The Mystery of the Gun Turret in the Desert

    SciTech Connect

    Hoffman, R. D.

    2015-11-30

    The mystery of the gun turret in the desert began with an ingenious idea: to develop a reusable open-air line of sight diagnostic device to support LLNL’s early nuclear weapons development efforts. Obtained from the Mare Island Navy Shipyard (MINS) in January 1957, the gun turret traveled by ship to the Naval Construction Battalion base at Port Hueneme, California, and then by truck to Area 2 in the Yucca Flats valley at the Nevada Nuclear Security Site (NNSS).

  10. Unbalanced field RF electron gun

    DOEpatents

    Hofler, Alicia

    2013-11-12

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  11. Aircraft Noise

    NASA Astrophysics Data System (ADS)

    Michel, Ulf; Dobrzynski, Werner; Splettstoesser, Wolf; Delfs, Jan; Isermann, Ullrich; Obermeier, Frank

    Aircraft industry is exposed to increasing public pressure aiming at a continuing reduction of aircraft noise levels. This is necessary to both compensate for the detrimental effect on noise of the expected increase in air traffic and improve the quality of living in residential areas around airports.

  12. Environmental Noise

    NASA Astrophysics Data System (ADS)

    Rumberg, Martin

    Environmental noise may be defined as unwanted sound that is caused by emissions from traffic (roads, air traffic corridors, and railways), industrial sites and recreational infrastructures, which may cause both annoyance and damage to health. Noise in the environment or community seriously affects people, interfering with daily activities at school, work and home and during leisure time.

  13. Hot hollow cathode gun assembly

    DOEpatents

    Zeren, J.D.

    1983-11-22

    A hot hollow cathode deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, the hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  14. Glue Guns: Aiming for Safety

    ERIC Educational Resources Information Center

    Roy, Ken

    2010-01-01

    While glue guns are very useful, there are safety issues. Regardless of the temperature setting, glue guns can burn skin. The teacher should demonstrate and supervise the use of glue guns and have a plan should a student get burned. There should be an initial first aid protocol in place, followed by a visit to the school nurse. An accident report…

  15. Vacuum vapor deposition gun assembly

    DOEpatents

    Zeren, Joseph D.

    1985-01-01

    A vapor deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, a hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  16. Children, Youth, and Gun Violence.

    ERIC Educational Resources Information Center

    Behrman, Richard E., Ed.

    2002-01-01

    This collection of articles summarizes knowledge and research about how gun violence affects children and youth and discusses which policies hold promise for reducing youth gun violence. The papers are: (1) "Statement of Purpose" (Richard E. Behrman); "Children, Youth, and Gun Violence: Analysis and Recommendations" (Kathleen Reich, Patti L.…

  17. Impacts of Western Area Power Administration`s power marketing alternatives on air quality and noise

    SciTech Connect

    Chun, K.C.; Chang, Y.S.; Rabchuk, J.A.

    1995-05-01

    The Western Area Power Administration, which is responsible for marketing electricity produced at the hydroelectric power-generating facilities operated by the Bureau of Reclamation on the Upper Colorado River, has proposed changes in the levels of its commitment (sales) of long-term firm capacity and energy to its customers. This report describes (1) the existing conditions of air resources (climate and meteorology, ambient air quality, and acoustic environment) of the region potentially affected by the proposed action and (2) the methodology used and the results of analyses conducted to assess the potential impacts on air resources of the proposed action and the commitment-level alternatives. Analyses were performed for the potential impacts of both commitment-level alternatives and supply options, which include combinations of electric power purchases and different operational scenarios of the hydroelectric power-generating facilities.

  18. Willingness to pay to avoid health risks from road-traffic-related air pollution and noise across five countries.

    PubMed

    Istamto, Tifanny; Houthuijs, Danny; Lebret, Erik

    2014-11-01

    We conducted a multi-country study to estimate the perceived economic values of traffic-related air pollution and noise health risks within the framework of a large European project. We used contingent valuation as a method to assess the willingness-to-pay (WTP) for both types of pollutants simultaneously. We asked respondents how much they would be willing to pay annually to avoid certain health risks from specific pollutants. Three sets of vignettes with different levels of information were provided prior to the WTP questions. These vignettes described qualitative general health risks, a quantitative single health risk related to a pollutant, and a quantitative scenario of combined health risks related to a pollutant. The mean WTP estimates to avoid road-traffic air pollution effects for the three vignettes were: €130 per person per year (pp/y) for general health risks, €80 pp/y for a half year shorter in life expectancy, and €330 pp/y to a 50% decrease in road-traffic air pollution. Their medians were €40 pp/y, €10 pp/y and €50 pp/y, respectively. The mean WTP estimates to avoid road-traffic noise effects for the three vignettes were: €90 pp/y for general health risks, €100 pp/y for a 13% increase in severe annoyance, and €320 pp/y for a combined-risk scenario related to an increase of a noise level from 50 dB to 65 dB. Their medians were €20 pp/y, €20 pp/y and €50 pp/y, respectively. Risk perceptions and attitudes as well as environmental and pollutant concerns significantly affected WTP estimates. The observed differences in crude WTP estimates between countries changed considerably when perception-related variables were included in the WTP regression models. For this reason, great care should be taken when performing benefit transfer from studies in one country to another. PMID:25146911

  19. Magnetron injection gun scaling

    SciTech Connect

    Lawson, W.

    1988-04-01

    Existing analytic design equations for magnetron injection guns (MIG's) are approximated to obtain a set of scaling laws. The constraints are chosen to examine the maximum peak power capabilities of MIG's. The scaling laws are compared with exact solutions of the design equations and are supported by MIG simulations.

  20. The Rail Gun.

    ERIC Educational Resources Information Center

    Stewart, Gay B.

    1996-01-01

    Presents a rail gun demonstration that addresses a broad group of educational goals in introductory electricity and magnetism. Uses a battery-powered circuit consisting of a movable conductor placed across two conducting rails in a magnetic field to review mechanics, foster approximate reasoning and lateral class discussion, and demonstrate the…

  1. Service Without Guns

    ERIC Educational Resources Information Center

    Eberly, Donald J.; Gal, Reuven

    2006-01-01

    "Service Without Guns"--by Donald J. Eberly and Reuven Gal with a guest chapter by Michael Sherraden--notes the many similarities between military service and civilian National Youth Service (NYS) and concludes that NYS can and should become as large and influential in the 21st Century as military service was in the 20th. The book examines the…

  2. Radar gun hazards

    SciTech Connect

    Not Available

    1991-12-20

    Radar guns - hand-held units used by the law to nail speeders - have been in use since the early '60s. Now they've been accused of causing cancer. Police officers in several states have so far filed eight suits against the manufacturer, claiming that they have contracted rare forms of cancer, such as of the eyelid and the testicle, from frequent proximity to the devices. Spurred by concerns expressed by police groups, researchers at the Rochester Institute of Technology are conducting what they believe to be the first research of its kind in the nation. Last month psychologist John Violanti, an expert in policy psychology and health, sent out a one-page survey to 6,000 active and retired police officers in New York State, asking them about their health and their use of radar guns. Violanti says melanoma, leukemia, and lymph node cancer may be linked to these as well as other electromagnetic devices. The Food and Drug Administration earlier this year issued a warning about radar guns, telling users not to operate them closer than 6 inches from the body. But this may not be a sufficient safeguard since the instruments can give off crisscrossing wave emissions within a police vehicle. The survey will be used to help determine if it would be safer to mount the guns, which are currently either hand-held or mounted on dashboards, outside troopers' cars.

  3. Gun control saves lives.

    PubMed

    Matzopoulos, Richard

    2016-01-01

    Reducing firearm mortality by means of stricter gun control is one of the most important short- to medium-term measures to address the burden of violence in South Africa, while longer-term interventions and policy measures take effect. PMID:27245735

  4. Gun Dealers, USA.

    ERIC Educational Resources Information Center

    Duker, Laurie; And Others

    In the United States, more than 11,500 adolescents' and young adults' lives are taken each year by firearms. Although Federal law prohibits minors from purchasing handguns, they typically get them by asking someone of legal age (18 years or older) to purchase them from one of the 256,771 Federally licensed gun dealers. This pamphlet answers…

  5. Airframe noise

    NASA Astrophysics Data System (ADS)

    Crighton, David G.

    1991-08-01

    Current understanding of airframe noise was reviewed as represented by experiment at model and full scale, by theoretical modeling, and by empirical correlation models. The principal component sources are associated with the trailing edges of wing and tail, deflected trailing edge flaps, flap side edges, leading edge flaps or slats, undercarriage gear elements, gear wheel wells, fuselage and wing boundary layers, and panel vibration, together with many minor protrusions like radio antennas and air conditioning intakes which may contribute significantly to perceived noise. There are also possibilities for interactions between the various mechanisms. With current engine technology, the principal airframe noise mechanisms dominate only at low frequencies, typically less than 1 kHz and often much lower, but further reduction of turbomachinery noise in particular may make airframe noise the principal element of approach noise at frequencies in the sensitive range.

  6. The polarized SRF gun experiment.

    SciTech Connect

    Kewisch,J.; Ben-Zvi, I.; Rao, T.; Burrill, A.; Pate, D.; Grover, R.; Todd, R.; Bluem, H.; Holmes, D.; Schultheiss, T.

    2007-09-10

    RF electron guns are capable of producing electron bunches with high brightness, which outperform DC electron guns and may even be able to provide electron beams for the ILC without the need for a damping ring. However, all successful existing guns for polarized electrons are DC guns because the environment inside an RF gun is hostile to the GaAs cathode material necessary for polarization. While the typical vacuum pressure in a DC gun is better than 10{sup -11} torr the vacuum in an RF gun is in the order of 10{sup -9} torr. Experiments at BINP Novosibirsk show that this leads to strong ion back-bombardment and generation of dark currents, which destroy the GaAs cathode in a short time. The situation might be much more favorable in a (super-conducting) SRF gun. The cryogenic pumping of the gun cavity walls may make it possible to maintain a vacuum close to 10{sup -12} torr, solving the problem of ion bombardment and dark currents. Of concern would be contamination of the gun cavity by evaporating cathode material. This report describes an experiment that Brookhaven National Laboratory (BNL) in collaboration with Advanced Energy Systems (AES) is conducting to answer these questions.

  7. Aircraft noise: accounting for changes in air traffic with time of day.

    PubMed

    Schäffer, Beat; Bütikofer, Rudolf; Plüss, Stefan; Thomann, Georg

    2011-01-01

    Aircraft noise contours are estimated using model calculations and, due to their impact on land use planning, they need to be highly accurate. During night time, not only the number and dominant types of aircraft may differ from daytime but also the flight paths flown may differ. To determine to which detail these variations in flight paths need to be considered, calculations were performed exemplarily for two airports using all available radar data over 1 year, taking into account their changes over the day. The results of this approach were compared with results of a simpler approach which does not consider such changes. While both calculations yielded similar results for the day and close to the airport, differences increased with distance as well as with the period of day (day

  8. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  9. Gun Attitudes and Fear of Crime.

    ERIC Educational Resources Information Center

    Heath, Linda; Weeks, Kyle; Murphy, Marie Mackay

    1997-01-01

    Using three studies, examined the relationship between attitudes toward guns and fear of crime. Findings indicate a connection between fear of crime and attitudes toward guns: people higher in fear of crime favored gun control. Results also established a relationship between stereotypical beliefs about gun victims and support for gun control. (RJM)

  10. Friction in rail guns

    NASA Technical Reports Server (NTRS)

    Kay, P. K.

    1984-01-01

    The influence of friction is included in the present equations describing the performance of an inductively driven rail gun. These equations, which have their basis in an empirical formulation, are applied to results from two different experiments. Only an approximate physical description of the problem is attempted, in view of the complexity of details in the interaction among forces of this magnitude over time periods of the order of milisecs.

  11. Some Measurements of Noise Transmission and Stress Response of a 0.020-Inch Duralumin Panel in the Presence of Air Flow

    NASA Technical Reports Server (NTRS)

    Kantarges, George T.

    1960-01-01

    Noise transmission measurements were made for a 0.020-inch panel with and without air flow on its surface. Tests were conducted with both an absorbent and reverberant chamber behind the panel. Panel stresses for some of these tests were also determined. Noise spectra obtained inside the absorbent chamber with flow attached and flow not attached to the panel appeared to contain several peaks corresponding in frequency to panel vibration modes. These peaks were notably absent when the chamber was reverberant. The noise reduction through the test panel measured with the aid of an absorbent chamber for the flow-not-attached case is in general agreement with values predicted by the theoretical weight law, which assumes negligible panel stiffness. Corresponding data for the flow-attached case do not follow the weight law but rather indicate less noise reduction at the high frequencies. The main stress responses of the panel without air flow occurred at its fundamental vibration mode. In the presence of air flow the main response occurs in a vibration mode having a node line perpendicular to the direction of air flow.

  12. Wisconsin SRF Electron Gun Commissioning

    SciTech Connect

    Bisognano, Joseph J.; Bissen, M.; Bosch, R.; Efremov, M.; Eisert, D.; Fisher, M.; Green, M.; Jacobs, K.; Keil, R.; Kleman, K.; Rogers, G.; Severson, M.; Yavuz, D. D.; Legg, Robert A.; Bachimanchi, Ramakrishna; Hovater, J. Curtis; Plawski, Tomasz; Powers, Thomas J.

    2013-12-01

    The University of Wisconsin has completed fabrication and commissioning of a low frequency (199.6 MHz) superconducting electron gun based on a quarter wave resonator (QWR) cavity. Its concept was optimized to be the source for a CW free electron laser facility. The gun design includes active tuning and a high temperature superconducting solenoid. We will report on the status of the Wisconsin SRF electron gun program, including commissioning experience and first beam measurements.

  13. Methods for coating conduit interior surfaces utilizing a thermal spray gun with extension arm

    DOEpatents

    Moore, Karen A.; Zatorski, Raymond A.

    2007-10-02

    Systems and methods for applying a coating to an interior surface of a conduit. In one embodiment, a spray gun configured to apply a coating is attached to an extension arm which may be inserted into the bore of a pipe. The spray gun may be a thermal spray gun adapted to apply a powder coating. An evacuation system may be used to provide a volume area of reduced air pressure for drawing overspray out of the pipe interior during coating. The extension arm as well as the spray gun may be cooled to maintain a consistent temperature in the system, allowing for more consistent coating.

  14. Systems and methods for coating conduit interior surfaces utilizing a thermal spray gun with extension arm

    DOEpatents

    Moore, Karen A.; Zatorski, Raymond A.

    2005-07-12

    Systems and methods for applying a coating to an interior surface of a conduit. In one embodiment, a spray gun configured to apply a coating is attached to an extension arm which may be inserted into the bore of a pipe. The spray gun may be a thermal spray gun adapted to apply a powder coating. An evacuation system may be used to provide a volume area of reduced air pressure for drawing overspray out of the pipe interior during coating. The extension arm as well as the spray gun may be cooled to maintain a consistent temperature in the system, allowing for more consistent coating.

  15. Gun muzzle blast and flash

    NASA Astrophysics Data System (ADS)

    Klingenberg, Guenter; Heimerl, Joseph M.

    A repository of fundamental experimental and analytical data concerning the complex phenomena associated with gun-muzzle blast and flash effects is presented, proceeding from gun muzzle signatures to modern gun-propulsion concepts, interior and transitional ballistics, and characterizations of blast-wave research and muzzle flash. Data are presented in support of a novel hypothesis which explains the ignition of secondary flash and elucidates the means for its suppression. Both chemical and mechanical (often competing) methods of flash suppression are treated. The historical work of Kesslau and Ladenburg is noted, together with French, British, Japanese and American research efforts and current techniques of experimental characterization for gun muzzle phenomena.

  16. Investigation of the potential effects of underwater noise from petroleum-industry activities on feeding humpback whale behavior. Final report

    SciTech Connect

    Malme, C.I.; Miles, P.R.; Tyack, P.; Clark, C.W.; Bird, J.E.

    1985-06-01

    An investigation was made of the potential effects of underwater noise from petroleum-industry activities on the behavior of feeding humpback whales in Frederick Sound and Stephens Passage, Alaska in August, 1984. Test sounds were a 100 cu. in. air gun and playbacks of recorded drillship, drilling platform, production platform, semi-submersible drill rig, and helicopter fly-over noise. Sound source levels and acoustic propagation losses were measured. The movement patterns of whales were determined by observations of whale-surfacing positions.

  17. Assessment of Impulsive and Continuous Low-Frequency Noise in Irish Waters.

    PubMed

    Beck, Suzanne; O'Brien, Joanne; Berrow, Simon; O'Connor, Ian; Wall, Dave

    2016-01-01

    As part of the European Union Marine Strategy Framework Directive (MSFD), member states are required to address noise pollution in the marine environment under Descriptor 11. This study aimed to provide a practical desk-based application of Descriptor 11 assessment, focusing on the main contributors of ocean noise pollution in Irish waters, seismic surveying and shipping. To highlight specific geographical areas subject to elevated levels of noise pollution, the proportion of days over a calendar year that seismic air guns were operational was calculated and the vessel density per 50-km(2) grids was determined across Ireland's exclusive economic zone (EEZ). Additionally, cetacean sighting data were used to determine the degree of spatial overlap between areas of elevated noise pollution and areas of cetacean abundance. PMID:26610946

  18. Computer programs for producing single-event aircraft noise data for specific engine power and meteorological conditions for use with USAF (United States Air Force) community noise model (NOISEMAP)

    NASA Astrophysics Data System (ADS)

    Mohlman, H. T.

    1983-04-01

    The Air Force community noise prediction model (NOISEMAP) is used to describe the aircraft noise exposure around airbases and thereby aid airbase planners to minimize exposure and prevent community encroachment which could limit mission effectiveness of the installation. This report documents two computer programs (OMEGA 10 and OMEGA 11) which were developed to prepare aircraft flight and ground runup noise data for input to NOISEMAP. OMEGA 10 is for flight operations and OMEGA 11 is for aircraft ground runups. All routines in each program are documented at a level useful to a programmer working with the code or a reader interested in a general overview of what happens within a specific subroutine. Both programs input normalized, reference aircraft noise data; i.e., data at a standard reference distance from the aircraft, for several fixed engine power settings, a reference airspeed and standard day meteorological conditions. Both programs operate on these normalized, reference data in accordance with user-defined, non-reference conditions to derive single-event noise data for 22 distances (200 to 25,000 feet) in a variety of physical and psycho-acoustic metrics. These outputs are in formats ready for input to NOISEMAP.

  19. Resonant optical gun.

    PubMed

    Maslov, A V; Bakunov, M I

    2014-05-01

    We propose a concept of a structure-a resonant optical gun-to realize an efficient propulsion of dielectric microparticles by light forces. The structure is based on a waveguide in which a reversal of the electromagnetic momentum flow of the incident mode is realized by exciting a whispering gallery resonance in the microparticle. The propelling force can reach the value up to the theoretical maximum of twice the momentum flow of the initial wave. The force density oscillates along the particle periphery and has very large amplitude. PMID:24784113

  20. Gun Concerns Personal for Duncan

    ERIC Educational Resources Information Center

    McNeil, Michele

    2013-01-01

    As U.S. Secretary of Education Arne Duncan works with other Obama administration officials on policy responses to the shootings at a Connecticut elementary school, he brings a personal and professional history that has acquainted him with the impact of gun violence. As schools chief in Chicago from 2001 to 2008, he was affected by the gun deaths…

  1. The associations between traffic-related air pollution and noise with blood pressure in children: results from the GINIplus and LISAplus studies.

    PubMed

    Liu, Chuang; Fuertes, Elaine; Tiesler, Carla M T; Birk, Matthias; Babisch, Wolfgang; Bauer, Carl-Peter; Koletzko, Sibylle; von Berg, Andrea; Hoffmann, Barbara; Heinrich, Joachim

    2014-01-01

    Although traffic emits both air pollution and noise, studies jointly examining the effects of both of these exposures on blood pressure (BP) in children are scarce. We investigated associations between land-use regression modeled long-term traffic-related air pollution and BP in 2368 children aged 10 years from Germany (1454 from Munich and 914 from Wesel). We also studied this association with adjustment of long-term noise exposure (defined as day-evening-night noise indicator "Lden" and night noise indicator "Lnight") in a subgroup of 605 children from Munich inner city. In the overall analysis including 2368 children, NO2, PM2.5 mass (particles with aerodynamic diameters below 2.5μm), PM10 mass (particles with aerodynamic diameters below 10μm) and PM2.5 absorbance were not associated with BP. When restricting the analysis to the subgroup of children with noise information (N=605), a significant association between NO2 and diastolic BP was observed (-0.88 (95% confidence interval: -1.67, -0.08)). However, upon adjusting the models for noise exposure, only noise remained independently and significantly positively associated with diastolic BP. Diastolic BP increased by 0.50 (-0.03, 1.02), 0.59 (0.05, 1.13), 0.55 (0.03, 1.07), and 0.58 (0.05, 1.11)mmHg for every five decibel increase in Lden and by 0.59 (-0.05, 1.22), 0.69 (0.04, 1.33), 0.64 (0.02, 1.27), and 0.68 (0.05, 1.32)mmHg for every five decibel increase in Lnight, in different models of NO2, PM2.5 mass, PM10 mass and PM2.5 absorbance as the main exposure, respectively. In conclusion, air pollution was not consistently associated with BP with adjustment for noise, noise was independently and positively associated with BP in children. PMID:24183515

  2. LCLS Gun Solenoid Design Considerations

    SciTech Connect

    Schmerge, John

    2010-12-10

    The LCLS photocathode rf gun requires a solenoid immediately downstream for proper emittance compensation. Such a gun and solenoid have been operational at the SSRL Gun Test Facility (GTF) for over eight years. Based on magnetic measurements and operational experience with the GTF gun solenoid multiple modifications are suggested for the LCLS gun solenoid. The modifications include adding dipole and quadrupole correctors inside the solenoid, increasing the bore to accommodate the correctors, decreasing the mirror plate thickness to allow the solenoid to move closer to the cathode, cutouts in the mirror plate to allow greater optical clearance with grazing incidence cathode illumination, utilizing pancake coil mirror images to compensate the first and second integrals of the transverse fields and incorporating a bipolar power supply to allow for proper magnet standardization and quick polarity changes. This paper describes all these modifications plus the magnetic measurements and operational experience leading to the suggested modifications.

  3. Preventing gun injuries in children.

    PubMed

    Crossen, Eric J; Lewis, Brenna; Hoffman, Benjamin D

    2015-02-01

    Firearms are involved in the injury and death of a large number of children each year from both intentional and unintentional causes. Gun ownership in homes with children is common, and pediatricians should incorporate evidence-based means to discuss firearms and protect children from gun-related injuries and violence. Safe storage of guns, including unloaded guns locked and stored separately from ammunition, can decrease risks to children, and effective tools are available that pediatricians can use in clinical settings to help decrease children's access to firearms. Furthermore, several community-based interventions led by pediatricians have effectively reduced firearm-related injury risks to children. Educational programs that focus on children's behavior around guns have not proven effective. PMID:25646308

  4. Electric arc welding gun

    DOEpatents

    Luttrell, Edward; Turner, Paul W.

    1978-01-01

    This invention relates to improved apparatus for arc welding an interior joint formed by intersecting tubular members. As an example, the invention is well suited for applications where many similar small-diameter vertical lines are to be welded to a long horizontal header. The improved apparatus includes an arc welding gun having a specially designed welding head which is not only very compact but also produces welds that are essentially free from rolled-over solidified metal. The welding head consists of the upper end of the barrel and a reversely extending electrode holder, or tip, which defines an acute angle with the barrel. As used in the above-mentioned example, the gun is positioned to extend upwardly through the vertical member and the joint to be welded, with its welding head disposed within the horizontal header. Depending on the design of the welding head, the barrel then is either rotated or revolved about the axis of the vertical member to cause the electrode to track the joint.

  5. Investigating the Link Between Gun Possession and Gun Assault

    PubMed Central

    Richmond, Therese S.; Culhane, Dennis P.; Ten Have, Thomas R.; Wiebe, Douglas J.

    2009-01-01

    Objectives. We investigated the possible relationship between being shot in an assault and possession of a gun at the time. Methods. We enrolled 677 case participants that had been shot in an assault and 684 population-based control participants within Philadelphia, PA, from 2003 to 2006. We adjusted odds ratios for confounding variables. Results. After adjustment, individuals in possession of a gun were 4.46 (P < .05) times more likely to be shot in an assault than those not in possession. Among gun assaults where the victim had at least some chance to resist, this adjusted odds ratio increased to 5.45 (P < .05). Conclusions. On average, guns did not protect those who possessed them from being shot in an assault. Although successful defensive gun uses occur each year, the probability of success may be low for civilian gun users in urban areas. Such users should reconsider their possession of guns or, at least, understand that regular possession necessitates careful safety countermeasures. PMID:19762675

  6. 5. GUN MOUNT ON TERRACE, EAST VIEW (1992). WrightPatterson ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. GUN MOUNT ON TERRACE, EAST VIEW (1992). - Wright-Patterson Air Force Base, Area B, Building 71, Power Plant Engine Test Torque Stands, Seventh Street between D & G Streets, Dayton, Montgomery County, OH

  7. Long-Term Air Pollution and Traffic Noise Exposures and Mild Cognitive Impairment in Older Adults: A Cross-Sectional Analysis of the Heinz Nixdorf Recall Study

    PubMed Central

    Tzivian, Lilian; Dlugaj, Martha; Winkler, Angela; Weinmayr, Gudrun; Hennig, Frauke; Fuks, Kateryna B.; Vossoughi, Mohammad; Schikowski, Tamara; Weimar, Christian; Erbel, Raimund; Jöckel, Karl-Heinz; Moebus, Susanne; Hoffmann, Barbara

    2016-01-01

    Background: Mild cognitive impairment (MCI) describes the intermediate state between normal cognitive aging and dementia. Adverse effects of air pollution (AP) on cognitive functions have been proposed, but investigations of simultaneous exposure to noise are scarce. Objectives: We analyzed the cross-sectional associations of long-term exposure to AP and traffic noise with overall MCI and amnestic (aMCI) and nonamnestic (naMCI) MCI. Methods: At the second examination of the population-based Heinz Nixdorf Recall study, cognitive assessment was completed in 4,086 participants who were 50–80 years old. Of these, 592 participants were diagnosed as having MCI (aMCI, n = 309; naMCI, n = 283) according to previously published criteria using five neuropsychological subtests. We assessed long-term residential concentrations for size-fractioned particulate matter (PM) and nitrogen oxides with land use regression, and for traffic noise [weighted 24-hr (LDEN) and night-time (LNIGHT) means]. Logistic regression models adjusted for individual risk factors were calculated to estimate the association of environmental exposures with MCI in single- and two-exposure models. Results: Most air pollutants and traffic noise were associated with overall MCI and aMCI. For example, an interquartile range increase in PM2.5 and a 10 A-weighted decibel [dB(A)] increase in LDEN were associated with overall MCI as follows [odds ratio (95% confidence interval)]: 1.16 (1.05, 1.27) and 1.40 (1.03, 1.91), respectively, and with aMCI as follows: 1.22 (1.08, 1.38) and 1.53 (1.05, 2.24), respectively. In two-exposure models, AP and noise associations were attenuated [e.g., for aMCI, PM2.5 1.13 (0.98, 1.30) and LDEN 1.46 (1.11, 1.92)]. Conclusions: Long-term exposures to air pollution and traffic noise were positively associated with MCI, mainly with the amnestic subtype. Citation: Tzivian L, Dlugaj M, Winkler A, Weinmayr G, Hennig F, Fuks KB, Vossoughi M, Schikowski T, Weimar C, Erbel R, Jöckel KH

  8. Gun shows and gun violence: fatally flawed study yields misleading results.

    PubMed

    Wintemute, Garen J; Hemenway, David; Webster, Daniel; Pierce, Glenn; Braga, Anthony A

    2010-10-01

    A widely publicized but unpublished study of the relationship between gun shows and gun violence is being cited in debates about the regulation of gun shows and gun commerce. We believe the study is fatally flawed. A working paper entitled "The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas" outlined this study, which found no association between gun shows and gun-related deaths. We believe the study reflects a limited understanding of gun shows and gun markets and is not statistically powered to detect even an implausibly large effect of gun shows on gun violence. In addition, the research contains serious ascertainment and classification errors, produces results that are sensitive to minor specification changes in key variables and in some cases have no face validity, and is contradicted by 1 of its own authors' prior research. The study should not be used as evidence in formulating gun policy. PMID:20724672

  9. Gun Shows and Gun Violence: Fatally Flawed Study Yields Misleading Results

    PubMed Central

    Hemenway, David; Webster, Daniel; Pierce, Glenn; Braga, Anthony A.

    2010-01-01

    A widely publicized but unpublished study of the relationship between gun shows and gun violence is being cited in debates about the regulation of gun shows and gun commerce. We believe the study is fatally flawed. A working paper entitled “The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas” outlined this study, which found no association between gun shows and gun-related deaths. We believe the study reflects a limited understanding of gun shows and gun markets and is not statistically powered to detect even an implausibly large effect of gun shows on gun violence. In addition, the research contains serious ascertainment and classification errors, produces results that are sensitive to minor specification changes in key variables and in some cases have no face validity, and is contradicted by 1 of its own authors’ prior research. The study should not be used as evidence in formulating gun policy. PMID:20724672

  10. Does Traffic-related Air Pollution Explain Associations of Aircraft and Road Traffic Noise Exposure on Children's Health and Cognition? A Secondary Analysis of the United Kingdom Sample From the RANCH Project

    PubMed Central

    Clark, Charlotte; Crombie, Rosanna; Head, Jenny; van Kamp, Irene; van Kempen, Elise; Stansfeld, Stephen A.

    2012-01-01

    The authors examined whether air pollution at school (nitrogen dioxide) is associated with poorer child cognition and health and whether adjustment for air pollution explains or moderates previously observed associations between aircraft and road traffic noise at school and children's cognition in the 2001–2003 Road Traffic and Aircraft Noise Exposure and Children's Cognition and Health (RANCH) project. This secondary analysis of a subsample of the United Kingdom RANCH sample examined 719 children who were 9–10 years of age from 22 schools around London's Heathrow airport for whom air pollution data were available. Data were analyzed using multilevel modeling. Air pollution exposure levels at school were moderate, were not associated with a range of cognitive and health outcomes, and did not account for or moderate associations between noise exposure and cognition. Aircraft noise exposure at school was significantly associated with poorer recognition memory and conceptual recall memory after adjustment for nitrogen dioxide levels. Aircraft noise exposure was also associated with poorer reading comprehension and information recall memory after adjustment for nitrogen dioxide levels. Road traffic noise was not associated with cognition or health before or after adjustment for air pollution. Moderate levels of air pollution do not appear to confound associations of noise on cognition and health, but further studies of higher air pollution levels are needed. PMID:22842719

  11. Does traffic-related air pollution explain associations of aircraft and road traffic noise exposure on children's health and cognition? A secondary analysis of the United Kingdom sample from the RANCH project.

    PubMed

    Clark, Charlotte; Crombie, Rosanna; Head, Jenny; van Kamp, Irene; van Kempen, Elise; Stansfeld, Stephen A

    2012-08-15

    The authors examined whether air pollution at school (nitrogen dioxide) is associated with poorer child cognition and health and whether adjustment for air pollution explains or moderates previously observed associations between aircraft and road traffic noise at school and children's cognition in the 2001-2003 Road Traffic and Aircraft Noise Exposure and Children's Cognition and Health (RANCH) project. This secondary analysis of a subsample of the United Kingdom RANCH sample examined 719 children who were 9-10 years of age from 22 schools around London's Heathrow airport for whom air pollution data were available. Data were analyzed using multilevel modeling. Air pollution exposure levels at school were moderate, were not associated with a range of cognitive and health outcomes, and did not account for or moderate associations between noise exposure and cognition. Aircraft noise exposure at school was significantly associated with poorer recognition memory and conceptual recall memory after adjustment for nitrogen dioxide levels. Aircraft noise exposure was also associated with poorer reading comprehension and information recall memory after adjustment for nitrogen dioxide levels. Road traffic noise was not associated with cognition or health before or after adjustment for air pollution. Moderate levels of air pollution do not appear to confound associations of noise on cognition and health, but further studies of higher air pollution levels are needed. PMID:22842719

  12. Reduction of noise generated by air conditioning and ventilation plants and transmitted to inhabited areas. [application of silencers

    NASA Technical Reports Server (NTRS)

    Harastaseanu, E.; Cristescu, G.; Mercea, F.

    1974-01-01

    The fans with which the conditioning and ventilation plants of weaving and spinning mills are equipped and the conditioning devices used in certain confection and knit wear departments of the textile industry generate loud noise. Solutions are presented for reducing the noise generated by the fans of ventilation and conditioning plants and transmitted to inhabited regions down to the admissible level, as well as the results obtained by experimental application of some noise reduction solutions in the conditioning plants of a spinning mill.

  13. High Intensity Polarized Electron Gun

    SciTech Connect

    Redwine, Robert P.

    2012-07-31

    The goal of the project was to investigate the possibility of building a very high intensity polarized electron gun for the Electron-Ion Collider. This development is crucial for the eRHIC project. The gun implements a large area cathode, ring-shaped laser beam and active cathode cooling. A polarized electron gun chamber with a large area cathode and active cathode cooling has been built and tested. A preparation chamber for cathode activation has been built and initial tests have been performed. Major parts for a load-lock chamber, where cathodes are loaded into the vacuum system, have been manufactured.

  14. Reduction of Gun Erosion and Correlation of Gun Erosion Measurements

    NASA Technical Reports Server (NTRS)

    Bogdanoff, Dave; Wercinski, Paul (Technical Monitor)

    1997-01-01

    Gun barrel erosion is serious problem with two-stage light gas guns. Excessive barrel erosion can lead to poor or failed launches and frequent barrel changes, with the corresponding down time. Also, excessive barrel erosion can limit the maximum velocity obtainable by loading down the hydrogen working gas with eroded barrel material. Guided by a CFD code, the operating conditions of the Ames 0.5-inch gun were modified to reduce barrel erosion. The changes implemented included: (1) reduction in the piston mass, powder mass and hydrogen fill pressure; and (2) reduction in pump tube volume, while maintaining hydrogen mass. The latter change was found, in particular, to greatly reduce barrel erosion. For muzzle velocity ranges of 6.1 - 6.9 km/sec, the barrel erosion was reduced by a factor of 10. Even for the higher muzzle velocity range of 7.0 - 8.2 km/sec, the barrel erosion was reduced by a factor of 4. Gun erosion data from the Ames 0.5-inch, 1.0-inch, and 1.5-inch guns operated over a wide variety of launch conditions was examined and it was found that this data could be correlated using four different parameters: normalized powder charge energy, normalized hydrogen energy density, normalized pump tube volume and barrel diameter. The development of the correlation and the steps used to collapse the experimental data are presented. Over a certain parameter range in the correlation developed, the barrel erosion per shot is found to increase very rapidly. The correlation should prove useful in the selection of gun operating conditions and the design of new guns. Representative shapes of eroded gun barrels are also presented.

  15. The Internal Ballistics of an Air Gun

    ERIC Educational Resources Information Center

    Denny, Mark

    2011-01-01

    The internal ballistics of a firearm or artillery piece considers the pellet, bullet, or shell motion while it is still inside the barrel. In general, deriving the muzzle speed of a gunpowder firearm from first principles is difficult because powder combustion is fast and it very rapidly raises the temperature of gas (generated by gunpowder…

  16. Nail-gun injuries. Accident, homicide, or suicide?

    PubMed

    McCorkell, S J; Harley, J D; Cummings, D

    1986-09-01

    It may be difficult to distinguish industrial accidents from suicide attempts or even assaults or homicide. Nail guns are relatively new industrial tools that can produce severe or fatal injuries. The configuration of the nail on patients' radiographs after such injuries can be helpful in determining the cause of injury. Steel nails that are bent are due to a ricochet and thus indicate accidental injury. Straight-nail injuries to the co-workers of nail-gun users are most likely due to over-penetration of the substance being nailed or accidental mid-air firing; however, intentional injury cannot be ruled out. Extremity injuries caused by straight steel nails in nail gun users are the result of carelessness or poor technique, but suicide should be considered when straight nails cause wounds to the chest, head, or abdomen. PMID:3788906

  17. Temporal association between federal gun laws and the diversion of guns to criminals in Milwaukee.

    PubMed

    Webster, Daniel W; Vernick, Jon S; Bulzacchelli, Maria T; Vittes, Katherine A

    2012-02-01

    The practices of licensed gun dealers can threaten the safety of urban residents by facilitating the diversion of guns to criminals. In 2003, changes to federal law shielded gun dealers from the release of gun trace data and provided other protections to gun dealers. The 14-month period during which the dealer did not sell junk guns was associated with a 68% reduction in the diversion of guns to criminals within a year of sale by the dealer and a 43% increase in guns diverted to criminals following sales by other dealers. The laws were associated with a 203% increase in the number of guns diverted to criminals within a year of sale by the gun store, which was the focus of this study. Policies which affect gun dealer accountability appeared to influence the diversion of guns to criminals. PMID:22218834

  18. The polarized SRF gun experiment

    SciTech Connect

    Kewisch,J.; Ben-Zvi, I.; Rao, T.; Burrill, A.; Pate, D.; Todd, R.; Wang, E.; Bluem, H.; Holmes, D.; Shultheiss, T.

    2008-10-01

    An experiment is under way to prove the feasibility of a super-conducting RF gun for the production of polarized electrons. We report on the progress of the experiment and on simulations predicting the possibility of success.

  19. NASA-Ames vertical gun

    NASA Technical Reports Server (NTRS)

    Schultz, P. H.

    1984-01-01

    A national facility, the NASA-Ames vertical gun range (AVGR) has an excellent reputation for revealing fundamental aspects of impact cratering that provide important constraints for planetary processes. The current logistics in accessing the AVGR, some of the past and ongoing experimental programs and their relevance, and the future role of this facility in planetary studies are reviewed. Publications resulting from experiments with the gun (1979 to 1984) are listed as well as the researchers and subjects studied.

  20. The case for moderate gun control.

    PubMed

    DeGrazia, David

    2014-03-01

    In addressing the shape of appropriate gun policy, this essay assumes for the sake of discussion that there is a legal and moral right to private gun ownership. My thesis is that, against the background of this right, the most defensible policy approach in the United States would feature moderate gun control. The first section summarizes the American gun control status quo and characterizes what I call "moderate gun control." The next section states and rebuts six leading arguments against this general approach to gun policy. The section that follows presents a positive case for moderate gun control that emphasizes safety in the home and society as well as rights whose enforcement entails some limits or qualifications on the right to bear arms. A final section shows how the recommended gun regulations address legitimate purposes, rather than imposing arbitrary restrictions on gun rights, and offers concluding reflections. PMID:24783322

  1. Reduction of aircraft noise in civil air transport by optimization of flight tracks and takeoff and approach procedures

    NASA Astrophysics Data System (ADS)

    Rottmann, Uwe

    1988-08-01

    Noise optimized design of operational flight procedures for effective noise pollution reduction is analyzed. Power cutback during certain stages of approach and takeoff, extension of distance between sound source and sound receiver, as well as diminution of sound impact time are optimized for specific flight procedures and routings. Five takeoff and three landing procedures are analyzed in acoustic effects. Sound immission is computed by NOISIMSIS (NOISe IMpact SImulation System), a simulation system especially created for this task, under consideration of aircraft type specified sound emission characteristics and performance data as well as different meteorological conditions. The investigations for the example of Frankfurt airport result in formulating a planning guideline with notes and impulses for activities in operational noise abatement.

  2. Large Bore Powder Gun Qualification (U)

    SciTech Connect

    Rabern, Donald A.; Valdiviez, Robert

    2012-04-02

    A Large Bore Powder Gun (LBPG) is being designed to enable experimentalists to characterize material behavior outside the capabilities of the NNSS JASPER and LANL TA-55 PF-4 guns. The combination of these three guns will create a capability to conduct impact experiments over a wide range of pressures and shock profiles. The Large Bore Powder Gun will be fielded at the Nevada National Security Site (NNSS) U1a Complex. The Complex is nearly 1000 ft below ground with dedicated drifts for testing, instrumentation, and post-shot entombment. To ensure the reliability, safety, and performance of the LBPG, a qualification plan has been established and documented here. Requirements for the LBPG have been established and documented in WE-14-TR-0065 U A, Large Bore Powder Gun Customer Requirements. The document includes the requirements for the physics experiments, the gun and confinement systems, and operations at NNSS. A detailed description of the requirements is established in that document and is referred to and quoted throughout this document. Two Gun and Confinement Systems will be fielded. The Prototype Gun will be used primarily to characterize the gun and confinement performance and be the primary platform for qualification actions. This gun will also be used to investigate and qualify target and diagnostic modifications through the life of the program (U1a.104 Drift). An identical gun, the Physics Gun, will be fielded for confirmatory and Pu experiments (U1a.102D Drift). Both guns will be qualified for operation. The Gun and Confinement System design will be qualified through analysis, inspection, and testing using the Prototype Gun for the majority of process. The Physics Gun will be qualified through inspection and a limited number of qualification tests to ensure performance and behavior equivalent to the Prototype gun. Figure 1.1 shows the partial configuration of U1a and the locations of the Prototype and Physics Gun/Confinement Systems.

  3. [Suicide with home-made gun].

    PubMed

    Safr, M; Hejna, P; Zátopková, L

    2009-04-01

    Three cases of suicide by single bullet injury to head by home-made guns with immediate incapacitation are reported in following article. Zip gun (home-made gun) is a improvised firearm, usually a handgun. Home-made guns are almost always single-shot, as the improvised construction sometimes makes them weak enough to be destroyed by the act of firing. Zip guns are mostly smoothbore. Zip gun injuries, although unique today, represent a special category of missile injury with atypical low velocity terminal ballistics. PMID:19534397

  4. Monte Carlo simulation of a quantum noise limited Čerenkov detector based on air-spaced light guiding taper for megavoltage x-ray imaging

    SciTech Connect

    Teymurazyan, A.; Rowlands, J. A.; Pang, G.

    2014-04-15

    Purpose: Electronic Portal Imaging Devices (EPIDs) have been widely used in radiation therapy and are still needed on linear accelerators (Linacs) equipped with kilovoltage cone beam CT (kV-CBCT) or MRI systems. Our aim is to develop a new high quantum efficiency (QE) Čerenkov Portal Imaging Device (CPID) that is quantum noise limited at dose levels corresponding to a single Linac pulse. Methods: Recently a new concept of CPID for MV x-ray imaging in radiation therapy was introduced. It relies on Čerenkov effect for x-ray detection. The proposed design consisted of a matrix of optical fibers aligned with the incident x-rays and coupled to an active matrix flat panel imager (AMFPI) for image readout. A weakness of such design is that too few Čerenkov light photons reach the AMFPI for each incident x-ray and an AMFPI with an avalanche gain is required in order to overcome the readout noise for portal imaging application. In this work the authors propose to replace the optical fibers in the CPID with light guides without a cladding layer that are suspended in air. The air between the light guides takes on the role of the cladding layer found in a regular optical fiber. Since air has a significantly lower refractive index (∼1 versus 1.38 in a typical cladding layer), a much superior light collection efficiency is achieved. Results: A Monte Carlo simulation of the new design has been conducted to investigate its feasibility. Detector quantities such as quantum efficiency (QE), spatial resolution (MTF), and frequency dependent detective quantum efficiency (DQE) have been evaluated. The detector signal and the quantum noise have been compared to the readout noise. Conclusions: Our studies show that the modified new CPID has a QE and DQE more than an order of magnitude greater than that of current clinical systems and yet a spatial resolution similar to that of current low-QE flat-panel based EPIDs. Furthermore it was demonstrated that the new CPID does not require an

  5. Studies of the effects of experimentally produced noise associated with oil and gas exploration and development on sea otters in California. Final report

    SciTech Connect

    Riedman, M.L.

    1983-11-15

    During the winter 1983 tape-recorded industrial noises associated with offshore oil and gas operations were projected underwater at Soberanes Point, California. Seismic-exploration sounds were produced using a multiple air gun array (4000 cu. in) and a single air gun (100 cu. in) along a 10-15 km transect paralleling the coastline from Rocky Point to Yankee Point. The behavior, density, and distribution of sea otters (Enhydra lutris) within the vicinity of the sound projection area were not affected by the acoustic experiments. Foraging and diving behaviors of sea otters were normal and undisturbed. There were no movements of otters away from the sound source or out of the sound projection vicinity during either the winter or spring acoustic experiments.

  6. Design and preliminary tests of a blade tip air mass injection system for vortex modification and possible noise reduction on a full-scale helicopter rotor

    NASA Technical Reports Server (NTRS)

    Pegg, R. J.; Hosier, R. N.; Balcerak, J. C.; Johnson, H. K.

    1975-01-01

    Full-scale tests were conducted on the Langley helicopter rotor test facility as part of a study to evaluate the effectiveness of a turbulent blade tip air mass injection system in alleviating the impulsive noise (blade slap) caused by blade-vortex interaction. Although blade-slap conditions could not be induced during these tests, qualitative results from flow visualization studies using smoke showed that the differential velocity between the jet velocity and the rotor tip speed was a primary parameter controlling the vortex modification.

  7. Effects of background noise on total noise annoyance

    NASA Technical Reports Server (NTRS)

    Willshire, K. F.

    1987-01-01

    Two experiments were conducted to assess the effects of combined community noise sources on annoyance. The first experiment baseline relationships between annoyance and noise level for three community noise sources (jet aircraft flyovers, traffic and air conditioners) presented individually. Forty eight subjects evaluated the annoyance of each noise source presented at four different noise levels. Results indicated the slope of the linear relationship between annoyance and noise level for the traffic noise was significantly different from that of aircraft and of air conditioner noise, which had equal slopes. The second experiment investigated annoyance response to combined noise sources, with aircraft noise defined as the major noise source and traffic and air conditioner noise as background noise sources. Effects on annoyance of noise level differences between aircraft and background noise for three total noise levels and for both background noise sources were determined. A total of 216 subjects were required to make either total or source specific annoyance judgements, or a combination of the two, for a wide range of combined noise conditions.

  8. Guns in the home: risky business.

    PubMed

    Wiebe, Douglas J

    2003-05-01

    One in three U.S. households contains at least one firearm. Gun owners cite two main reasons for having a gun: hunting and self-protection. A majority of handgun owners believe that they are protecting their homes and families against violent assaults. But in a country where the majority of homicides and suicides involve a gun, it is reasonable to question whether access to a gun increases or decreases the risk of violent death. This Issue Brief describes case-control studies that investigate links between gun availability and gun death, and supports earlier findings that people with guns in their homes appear to increase their risk of being shot fatally (intentionally or unintentionally) or taking their own life with a gun. PMID:12828174

  9. States with More Gun Owners Have More Gun-Related Suicides: Study

    MedlinePlus

    ... medlineplus/news/fullstory_158931.html States With More Gun Owners Have More Gun-Related Suicides: Study But only association was found, ... HealthDay News) -- In states where there are more gun owners, there are also more gun-related suicides, ...

  10. States with More Gun Owners Have More Gun-Related Suicides: Study

    MedlinePlus

    ... gov/news/fullstory_158931.html States With More Gun Owners Have More Gun-Related Suicides: Study But only association was found, ... HealthDay News) -- In states where there are more gun owners, there are also more gun-related suicides, ...

  11. Automatic targeting of plasma spray gun

    DOEpatents

    Abbatiello, Leonard A.; Neal, Richard E.

    1978-01-01

    A means for monitoring the material portion in the flame of a plasma spray gun during spraying operations is provided. A collimated detector, sensitive to certain wavelengths of light emission, is used to locate the centroid of the material with each pass of the gun. The response from the detector is then relayed to the gun controller to be used to automatically realign the gun.

  12. DIRECT TRACE ANALYSIS OF VOLATILE ORGANIC COMPOUNDS IN AIR USING ION TRAP MASS SPECTROMETERS WITH FILTERED NOISE FIELDS

    EPA Science Inventory

    Two ion trap mass spectrometers and direct air sampling interfaces are being evaluated in the laboratory for monitoring toxic air pollutants in real time. he mass spectrometers are the large, laboratory-based Finnigan MAT ion trap (ITMS) and the compact, field-deployable Teledyne...

  13. Comparative intelligibility of speech materials processed by standard Air Force voice communication systems in the presence of simulated cockpit noise

    NASA Astrophysics Data System (ADS)

    Moore, T. J.; Nixon, C. W.; McKinley, R. L.

    1981-06-01

    Among the systems evaluated was the ARC-164 radio which will serve as the reference system against which the performance of jam-resistant, secure systems developed in the immediate future will be compared. Relative differences found between male and female talkers under various levels of simulated cockpit noise are reported.

  14. Unintentional Gun Deaths among Children. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Children are at risk of being killed or injured by a gun if their parents own a gun because many guns obtained for self-defense are kept loaded and within reach of children. This brief fact sheet presents statistical information relating to accidental deaths involving young people and firearms. Safety measures are suggested for preventing…

  15. Making noise comfortable for people

    SciTech Connect

    Leventhall, H.G.; Wise, S.S.

    1998-10-01

    Typical HVAC noise may produce an uncomfortable environment, leading to the associated problems of general dissatisfaction and reduced productivity. It is not sufficient to have good thermal, lighting, and air cleanliness conditions if the noise is disturbing. In this paper, noise comfort is considered, with special emphasis on the developing criteria for low-frequency noise.

  16. High gradient rf gun studies of CsBr photocathodes

    SciTech Connect

    Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; Corbett, Jeff; Hartmann, Nick; Pianetta, Piero A.; Hesselink, Lambertus; Schmerge, John F.

    2015-04-03

    CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV/m fields without breaking down or emitting dark current. They can operate in 2×10⁻⁹ torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

  17. High gradient rf gun studies of CsBr photocathodes

    NASA Astrophysics Data System (ADS)

    Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; Corbett, Jeff; Hartmann, Nick; Pianetta, Piero A.; Hesselink, Lambertus; Schmerge, John F.

    2015-04-01

    CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV /m fields without breaking down or emitting dark current. They can operate in 2 ×10-9 torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

  18. Temperature Controller System for Gas Gun Targets

    NASA Astrophysics Data System (ADS)

    Bucholtz, S. M.; Gehr, R. J.; Rupp, T. D.; Sheffield, S. A.; Robbins, D. L.

    2006-07-01

    A temperature controller system capable of heating and cooling gas gun targets over the range -75°C to +120°C was designed and tested. The system uses cold nitrogen gas from a liquid nitrogen Dewar for cooling and compressed air for heating. Two gas flow heaters control the gas temperature for both heating and cooling. One heater controls the temperature of the target mounting plate and the other the temperature of a copper tubing coil surrounding the target. Each heater is separately adjustable, so the target material will achieve a uniform temperature throughout its volume. A magnetic gauge membrane with integrated thermocouples was developed to measure the internal temperature of the target. Using this system, multiple magnetic gauge shock experiments, including equation-of-state measurements and shock initiation of high explosives, can be performed over a range of initial temperatures. Successful heating and cooling tests were completed on Teflon samples.

  19. Guns in Schools. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Common reasons that young people choose to carry firearms outside of school--protection, intimidation of others, or to be like their peers--are the same reasons they carry guns into the school. This fact sheet presents statistics regarding the prevalence of firearms amongst students in American schools, including: shooting fatalities and woundings…

  20. Noise source detection and measurement in a supersonic air jet using Ultra-high Speed Rainbow Schlieren Deflectometry

    NASA Astrophysics Data System (ADS)

    Rajora, Manik; Agrawal, Ajay; Mitchell, William; Kolhe, Pankaj

    2012-11-01

    Supersonic jets emit noise from various regions including the shear layer containing vortical structures, various shock cell structures in the near field and the downstream jet core breakdown region. Sound waves emitted from these various regions interact with each other and produce distinct noise spectra away from the jet, which depends upon the measurement location. Typically sound is detected by intrusive probes that provide measurements at a specific location, which makes it difficult to identify the origination point of such noise in a supersonic jet. In this study, an ultra-high speed Rainbow Schlieren Deflectometry (RSD) technique has been developed to optically visualize not only the supersonic jet flow but also the sound waves emanating from it in real time. Color schlieren images are acquired at up to 250,000 frames per second to capture the sound wave propagation with adequate spatial resolution. Optical components of the system were optimized to improve the spatial and temporal resolutions and hence, the schlieren video quality. To the best of our knowledge, this is the first time sound wave propagation from supersonic jets has been recorded in real time on a schlieren video. Acquired color schlieren images are amenable to quantitative analysis, and can provide data on sound power and sound wave frequency across the whole field. This project was funded by NSF REU 1062611 and Department of Energy for Institue for Sustainable Energy EE003134.

  1. RF Design of the LCLS Gun

    SciTech Connect

    Limborg-Deprey, C

    2010-12-13

    Final dimensions for the LCLS RF gun are described. This gun, referred to as the LCLS gun, is a modified version of the UCLA/BNL/SLAC 1.6 cell S-Band RF gun [1], referred to as the prototype gun. The changes include a larger mode separation (15 MHz for the LCLS gun vs. 3.5 MHz for the prototype gun), a larger radius at the iris between the 2 cells, a reduced surface field on the curvature of the iris between the two cells, Z power coupling, increased cooling channels for operation at 120 Hz, dual rf feed, deformation tuning of the full cell, and field probes in both cells. Temporal shaping of the klystron pulse, to reduce the average power dissipated in the gun, has also been adopted. By increasing the mode separation, the amplitude of the 0-mode electric field on the cathode decreases from 10% of the peak on axis field for the prototype gun to less than 3% for the LCLS gun for the steady state fields. Beam performance is improved as shown by the PARMELA simulations. The gun should be designed to accept a future load lock system. Modifications follow the recommendations of our RF review committee [2]. Files and reference documents are compiled in Section IV.

  2. Granny, (don't) get your gun: competency issues in gun ownership by older adults.

    PubMed

    Greene, Edith; Bornstein, Brian H; Dietrich, Hannah

    2007-01-01

    This article explores the possible risks associated with gun ownership by older adults. We summarize existing regulations on who may own firearms, especially with respect to age. We then present data on older gun owners and violence committed by older adults in general, followed by a discussion of gun violence perpetrated by gun owners whose functional and cognitive abilities have declined, perhaps as a result of dementia. For comparison purposes, we review regulations on driving among older adults, drawing parallels to gun ownership. The paper concludes with recommendations for ensuring the safety of older gun owners and others, balanced against citizens' right to bear arms, and with some directions for research. PMID:17559168

  3. Core Noise Reduction

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduce-Perceived-Noise Technical Challenge; and the current research activities in the core noise area. Recent work1 on the turbine-transmission loss of combustor noise is briefly described, two2,3 new NRA efforts in the core-noise area are outlined, and an effort to develop CMC-based acoustic liners for broadband noise reduction suitable for turbofan-core application is delineated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. The Subsonic Fixed Wing Project's Reduce-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries.

  4. A gasdynamic gun driven by gaseous detonation

    NASA Astrophysics Data System (ADS)

    Li, Jinping; Chen, Hong; Zhang, Shizhong; Zhang, Xiaoyuan; Yu, Hongru

    2016-01-01

    A gasdynamic gun driven by gaseous detonation was developed to address the disadvantages of the insufficient driving capability of high-pressure gas and the constraints of gunpowder. The performance of this gasdynamic gun was investigated through experiments and numerical simulations. Much more powerful launching capability was achieved by this gun relative to a conventional high-pressure gas gun, owing to the use of the chemical energy of the driver gas. To achieve the same launching condition, the initial pressure required for this gun was an order of magnitude lower than that for a gun driven by high-pressure H2. Because of the presence of the detonation, however, a more complex internal ballistic process of this gun was observed. Acceleration of projectiles for this gun was accompanied by a series of impulse loads, in contrast with the smooth acceleration for a conventional one, which indicates that this gun should be used conditionally. The practical feasibility of this gun was verified by experiments. The experiments demonstrated the convenience of taking advantage of the techniques developed for detonation-driven shock tubes and tunnels.

  5. A gasdynamic gun driven by gaseous detonation.

    PubMed

    Li, Jinping; Chen, Hong; Zhang, Shizhong; Zhang, Xiaoyuan; Yu, Hongru

    2016-01-01

    A gasdynamic gun driven by gaseous detonation was developed to address the disadvantages of the insufficient driving capability of high-pressure gas and the constraints of gunpowder. The performance of this gasdynamic gun was investigated through experiments and numerical simulations. Much more powerful launching capability was achieved by this gun relative to a conventional high-pressure gas gun, owing to the use of the chemical energy of the driver gas. To achieve the same launching condition, the initial pressure required for this gun was an order of magnitude lower than that for a gun driven by high-pressure H2. Because of the presence of the detonation, however, a more complex internal ballistic process of this gun was observed. Acceleration of projectiles for this gun was accompanied by a series of impulse loads, in contrast with the smooth acceleration for a conventional one, which indicates that this gun should be used conditionally. The practical feasibility of this gun was verified by experiments. The experiments demonstrated the convenience of taking advantage of the techniques developed for detonation-driven shock tubes and tunnels. PMID:26827358

  6. Effects of a gun dealer's change in sales practices on the supply of guns to criminals.

    PubMed

    Webster, Daniel W; Vernick, Jon S; Bulzacchelli, Maria T

    2006-09-01

    Licensed gun dealers are a major conduit for gun trafficking. Prior to May 1999, a single gun store sold more than half of the guns recovered from criminals in Milwaukee, WI, shortly following retail sale. On May 10, 1999, the store stopped selling small, inexpensive handguns popular with criminals, often called "Saturday night specials." The purpose of this study was to estimate the effect of this gun store's changed sales practices on criminals' acquisition of new guns. We used an interrupted time-series design with comparisons to test for changes in the number of guns that police recovered from criminals within a year of retail sale following the gun dealer's new sales policy. The dealer's changed sales policy was associated with a 96% decrease in recently sold, small, inexpensive handguns use in crime in Milwaukee, a 73% decrease in crime guns recently sold by this dealer, and a 44% decrease in the flow of all new, trafficked guns to criminals in Milwaukee. The findings demonstrate the substantial impact that a single gun store's sales practices can have on the supply of new guns to criminals. Proposed anti-gun-trafficking efforts in other cities could benefit from targeting problem retail outlets. PMID:16937085

  7. Effects of a Gun Dealer's Change in Sales Practices on the Supply of Guns to Criminals

    PubMed Central

    Vernick, Jon S.; Bulzacchelli, Maria T.

    2006-01-01

    Licensed gun dealers are a major conduit for gun trafficking. Prior to May 1999, a single gun store sold more than half of the guns recovered from criminals in Milwaukee, WI, shortly following retail sale. On May 10, 1999, the store stopped selling small, inexpensive handguns popular with criminals, often called “Saturday night specials.” The purpose of this study was to estimate the effect of this gun store's changed sales practices on criminals' acquisition of new guns. We used an interrupted time-series design with comparisons to test for changes in the number of guns that police recovered from criminals within a year of retail sale following the gun dealer's new sales policy. The dealer's changed sales policy was associated with a 96% decrease in recently sold, small, inexpensive handguns use in crime in Milwaukee, a 73% decrease in crime guns recently sold by this dealer, and a 44% decrease in the flow of all new, trafficked guns to criminals in Milwaukee. The findings demonstrate the substantial impact that a single gun store's sales practices can have on the supply of new guns to criminals. Proposed anti-gun-trafficking efforts in other cities could benefit from targeting problem retail outlets. PMID:16937085

  8. Core-Noise

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2010-01-01

    This presentation is a technical progress report and near-term outlook for NASA-internal and NASA-sponsored external work on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system level noise metrics for the 2015, 2020, and 2025 timeframes; the emerging importance of core noise and its relevance to the SFW Reduced-Noise-Aircraft Technical Challenge; the current research activities in the core-noise area, with some additional details given about the development of a high-fidelity combustion-noise prediction capability; the need for a core-noise diagnostic capability to generate benchmark data for validation of both high-fidelity work and improved models, as well as testing of future noise-reduction technologies; relevant existing core-noise tests using real engines and auxiliary power units; and examples of possible scenarios for a future diagnostic facility. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Noise-Aircraft Technical Challenge aims to enable concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical for enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor designs could increase

  9. Advanced computer technology - An aspect of the Terminal Configured Vehicle program. [air transportation capacity, productivity, all-weather reliability and noise reduction improvements

    NASA Technical Reports Server (NTRS)

    Berkstresser, B. K.

    1975-01-01

    NASA is conducting a Terminal Configured Vehicle program to provide improvements in the air transportation system such as increased system capacity and productivity, increased all-weather reliability, and reduced noise. A typical jet transport has been equipped with highly flexible digital display and automatic control equipment to study operational techniques for conventional takeoff and landing aircraft. The present airborne computer capability of this aircraft employs a multiple computer simple redundancy concept. The next step is to proceed from this concept to a reconfigurable computer system which can degrade gracefully in the event of a failure, adjust critical computations to remaining capacity, and reorder itself, in the case of transients, to the highest order of redundancy and reliability.

  10. Noise generated by a flight weight, air flow control valve in a vertical takeoff and landing aircraft thrust vectoring system

    NASA Technical Reports Server (NTRS)

    Huff, Ronald G.

    1989-01-01

    Tests were conducted in the NASA Lewis Research Center's Powered Lift Facility to experimentally evaluate the noise generated by a flight weight, 12 in. butterfly valve installed in a proposed vertical takeoff and landing thrust vectoring system. Fluctuating pressure measurements were made in the circular duct upstream and downstream of the valve. This data report presents the results of these tests. The maximum overall sound pressure level is generated in the duct downstream of the valve and reached a value of 180 dB at a valve pressure ratio of 2.8. At the higher valve pressure ratios the spectra downstream of the valve is broad banded with its maximum at 1000 Hz.

  11. HVAC equipment and noise

    SciTech Connect

    Cerami, V.J.

    1996-03-01

    The purpose of this article is to define how the selection of HVAC equipment and layout impact the achievable noise criteria (NC) levels in occupied spaces. It will focus on the design of HVAC systems that employ floor-by-floor air handling/air conditioning units and their acoustical ramifications. This is of increasing importance since tenants require incorporation of noise limits in lease agreements.

  12. Impulse noise trauma during army weapon firing.

    PubMed

    Munjal, K R; Singh, V P

    1997-04-01

    A 100 infanty personnel firing modern weapons such as the Anti Tank Guided Missile, 106mm Recoiless Gun (RCL), 84mm Rocket Launcher (RL) and 81mm Mortar were studied for the effect of impulse noise on the ear and the evolution of the Temporary Threshold Shift (TTS), Recovery Time (RT) and Permanent Threshold Shift (PTS) was traced. PMID:23119288

  13. X-Band RF Gun Development

    SciTech Connect

    Vlieks, Arnold; Dolgashev, Valery; Tantawi, Sami; Anderson, Scott; Hartemann, Fred; Marsh, Roark; /LLNL, Livermore

    2012-06-22

    In support of the MEGa-ray program at LLNL and the High Gradient research program at SLAC, a new X-band multi-cell RF gun is being developed. This gun, similar to earlier guns developed at SLAC for Compton X-ray source program, will be a standing wave structure made of 5.5 cells operating in the pi mode with copper cathode. This gun was designed following criteria used to build SLAC X-band high gradient accelerating structures. It is anticipated that this gun will operate with surface electric fields on the cathode of 200 MeV/m with low breakdown rate. RF will be coupled into the structure through a final cell with symmetric duel feeds and with a shape optimized to minimize quadrupole field components. In addition, geometry changes to the original gun, operated with Compton X-ray source, will include a wider RF mode separation, reduced surface electric and magnetic fields.

  14. Improved DC Gun Insulator Assembly

    SciTech Connect

    Sah, R.; Dudas, A.; Neubauer, M. L.; Poelker, M.; Surles-Law, K. E.L.

    2010-05-23

    Many user fa­cil­i­ties such as syn­chrotron ra­di­a­tion light sources and free elec­tron lasers re­quire ac­cel­er­at­ing struc­tures that sup­port elec­tric fields of 10-100 MV/m, es­pe­cial­ly at the start of the ac­cel­er­a­tor chain where ce­ram­ic in­su­la­tors are used for very high gra­di­ent DC guns. These in­su­la­tors are dif­fi­cult to man­u­fac­ture, re­quire long com­mis­sion­ing times, and often ex­hib­it poor re­li­a­bil­i­ty. Two tech­ni­cal ap­proach­es to solv­ing this prob­lem will be in­ves­ti­gat­ed. First­ly, in­vert­ed ce­ram­ics offer so­lu­tions for re­duced gra­di­ents be­tween the elec­trodes and ground. An in­vert­ed de­sign will be pre­sent­ed for 350 kV, with max­i­mum gra­di­ents in the range of 5-10 MV/m. Sec­ond­ly, novel ce­ram­ic man­u­fac­tur­ing pro­cess­es will be stud­ied, in order to pro­tect triple junc­tion lo­ca­tions from emis­sion, by ap­ply­ing a coat­ing with a bulk re­sis­tiv­i­ty. The pro­cess­es for cre­at­ing this coat­ing will be op­ti­mized to pro­vide pro­tec­tion as well as be used to coat a ce­ram­ic with an ap­pro­pri­ate gra­di­ent in bulk re­sis­tiv­i­ty from the vac­u­um side to the air side of an HV stand­off ce­ram­ic cylin­der. Ex­am­ple in­su­la­tor de­signs are being com­put­er mod­elled, and in­su­la­tor sam­ples are being man­u­fac­tured and test­ed

  15. Core Noise - Increasing Importance

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduced-Perceived-Noise Technical Challenge; and the current research activities in the core-noise area, with additional details given about the development of a high-fidelity combustor-noise prediction capability as well as activities supporting the development of improved reduced-order, physics-based models for combustor-noise prediction. The need for benchmark data for validation of high-fidelity and modeling work and the value of a potential future diagnostic facility for testing of core-noise-reduction concepts are indicated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor

  16. Racism, Gun Ownership and Gun Control: Biased Attitudes in US Whites May Influence Policy Decisions

    PubMed Central

    O’Brien, Kerry; Forrest, Walter; Lynott, Dermot; Daly, Michael

    2013-01-01

    Objective Racism is related to policies preferences and behaviors that adversely affect blacks and appear related to a fear of blacks (e.g., increased policing, death penalty). This study examined whether racism is also related to gun ownership and opposition to gun controls in US whites. Method The most recent data from the American National Election Study, a large representative US sample, was used to test relationships between racism, gun ownership, and opposition to gun control in US whites. Explanatory variables known to be related to gun ownership and gun control opposition (i.e., age, gender, education, income, conservatism, anti-government sentiment, southern vs. other states, political identification) were entered in logistic regression models, along with measures of racism, and the stereotype of blacks as violent. Outcome variables included; having a gun in the home, opposition to bans on handguns in the home, support for permits to carry concealed handguns. Results After accounting for all explanatory variables, logistic regressions found that for each 1 point increase in symbolic racism there was a 50% increase in the odds of having a gun at home. After also accounting for having a gun in the home, there was still a 28% increase in support for permits to carry concealed handguns, for each one point increase in symbolic racism. The relationship between symbolic racism and opposition to banning handguns in the home (OR1.27 CI 1.03,1.58) was reduced to non-significant after accounting for having a gun in the home (OR1.17 CI.94,1.46), which likely represents self-interest in retaining property (guns). Conclusions Symbolic racism was related to having a gun in the home and opposition to gun control policies in US whites. The findings help explain US whites’ paradoxical attitudes towards gun ownership and gun control. Such attitudes may adversely influence US gun control policy debates and decisions. PMID:24204867

  17. Improved Orifice Plate for Spray Gun

    NASA Technical Reports Server (NTRS)

    Cunningham, W.

    1986-01-01

    Erratic spray pattern of commercial spray gun changed to repeatable one by simple redesign of two parts. In modified spray gun orifice plate and polytetrafluoroethylene bushing redesigned to assure centering and alignment with nozzle. Such improvement useful in many industrial applications requiring repeatable spray patterns. Might include spraying of foam insulation, paint, other protective coatings, detergents, abrasives, adhesives, process chemicals, or fuels. Unmodified spray gun produces erratic spray because lateral misalignment between orifice plate and nozzle.

  18. Health and Gun Violence. Guns as a Public-Health Issue.

    ERIC Educational Resources Information Center

    Duran, Victoria

    1994-01-01

    Violence in all settings has reached epidemic proportions. Most shootings are committed by friends or relatives following an argument or when playing with guns. The public needs education about nonviolent ways of coping with anger and about the high cost of gun violence. Suggestions for avoiding gun violence and the PTA position on firearms are…

  19. Aircraft noise - Different ways to monitor the noise load

    NASA Astrophysics Data System (ADS)

    Bekebrede, G.

    Measures taken by the Dutch government to reduce aircraft-noise disturbances including the establishment of noise zones in which subsequent building is forbidden, while already existing homes are provided with noise insulation are discussed. To ensure accurate noise monitoring, the following recommendations were made by the NLR: (1) regular noise load calculations, utilizing aircraft noise and performance data, the air traffic mix, and flight route information; (2) flight track monitoring, performed by a computerized Flight Track and Aircraft Noise Monitoring System which identifies all aircraft deviating from the prescribed track (i.e., flying over congested regions); and (3) actual noise monitoring, to guard the noise level at a specific noise-sensitive area in close proximity to the airfield, such as a hospital.

  20. From gun politics to self-defense politics: a feminist critique of the great gun debate.

    PubMed

    Carlson, Jennifer D

    2014-03-01

    This article calls attention to a problematic binary produced by public debates surrounding gun rights and gun control-namely, that women must choose armed self-protection or no self-protection at all. I argue that both anti- and pro-gun discourses, drawing on and reproducing race and class privileges, use assumptions about women's physical inferiority to further their agendas. I highlight how both sides have used guns as the proxy for self-defense and conclude by calling for a shift in public discourse to focus on the broader question of the right to self-defense rather than the narrower question of gun rights. PMID:24686128

  1. Core-Noise Research

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2012-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015 (N+1), 2020 (N+2), and 2025 (N+3) timeframes; SFW strategic thrusts and technical challenges; SFW advanced subsystems that are broadly applicable to N+3 vehicle concepts, with an indication where further noise research is needed; the components of core noise (compressor, combustor and turbine noise) and a rationale for NASA's current emphasis on the combustor-noise component; the increase in the relative importance of core noise due to turbofan design trends; the need to understand and mitigate core-noise sources for high-efficiency small gas generators; and the current research activities in the core-noise area, with additional details given about forthcoming updates to NASA's Aircraft Noise Prediction Program (ANOPP) core-noise prediction capabilities, two NRA efforts (Honeywell International, Phoenix, AZ and University of Illinois at Urbana-Champaign, respectively) to improve the understanding of core-noise sources and noise propagation through the engine core, and an effort to develop oxide/oxide ceramic-matrix-composite (CMC) liners for broadband noise attenuation suitable for turbofan-core application. Core noise must be addressed to ensure that the N+3 noise goals are met. Focused, but long-term, core-noise research is carried out to enable the advanced high-efficiency small gas-generator subsystem, common to several N+3 conceptual designs, needed to meet NASA's technical challenges. Intermediate updates to prediction tools are implemented as the understanding of the source structure and engine-internal propagation effects is improved. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The

  2. Crafting a Gauss Gun Demonstration

    NASA Astrophysics Data System (ADS)

    Blodgett, Matthew E.; Blodgett, E. D.

    2006-12-01

    A Gauss Gun launches a ferromagnetic projectile using a pulsed electromagnet. This demonstration provides a nice counterpoint to the popular Thompson's jumping ring demonstration, which launches a nonferromagnetic ring via repulsion of an induced current. The pulsed current must be short enough in duration so that the projectile is not retarded by lingering current in the launch solenoid, but also large enough to provide a suitably impressive velocity. This project involved an iterative design process, as we worked through balancing all the different design criteria. We recommend it as a very nice electronics design project which will produce a very portable and enjoyable demonstration. AAPT sponsor Earl Blodgett.

  3. The Xygra gun simulation tool.

    SciTech Connect

    Garasi, Christopher Joseph; Lamppa, Derek C.; Aubuchon, Matthew S.; Shirley, David Noyes; Robinson, Allen Conrad; Russo, Thomas V.

    2008-12-01

    Inductive electromagnetic launchers, or coilguns, use discrete solenoidal coils to accelerate a coaxial conductive armature. To date, Sandia has been using an internally developed code, SLINGSHOT, as a point-mass lumped circuit element simulation tool for modeling coilgun behavior for design and verification purposes. This code has shortcomings in terms of accurately modeling gun performance under stressful electromagnetic propulsion environments. To correct for these limitations, it was decided to attempt to closely couple two Sandia simulation codes, Xyce and ALEGRA, to develop a more rigorous simulation capability for demanding launch applications. This report summarizes the modifications made to each respective code and the path forward to completing interfacing between them.

  4. Electromagnetic Gun With Commutated Coils

    NASA Technical Reports Server (NTRS)

    Elliott, David G.

    1991-01-01

    Proposed electromagnetic gun includes electromagnet coil, turns of which commutated in sequence along barrel. Electrical current fed to two armatures by brushes sliding on bus bars in barrel. Interaction between armature currents and magnetic field from coil produces force accelerating armature, which in turn, pushes on projectile. Commutation scheme chosen so magnetic field approximately coincides and moves with cylindrical region defined by armatures. Scheme has disadvantage of complexity, but in return, enables designer to increase driving magnetic field without increasing armature current. Attainable muzzle velocity increased substantially.

  5. Guns and High Gas Output Devices Panel: Introduction

    NASA Technical Reports Server (NTRS)

    Simmons, Ronald L.; Kaste, Pamela J.

    2000-01-01

    A new panel known as the Guns and High Gas Output Panel was organized in 1999 under the auspices of the JANNAF Propellant and Characterization SubCommittee (PDCS). This is an introduction to our first meeting, purpose of the panel, and the scope of activities to be covered. The primary purpose of the panel is very simple: to provide a single focal point for interfacing Government Laboratories (Department of Defense and Department of Energy) and commercial industry researchers to share R&D activities and findings (i.e. facilitate the exchange of information) specifically aimed at gun-launched propulsion and high-gas output devices (gas generators and air bag inflators). Specific areas of interest included in the Panel's scope (and the Technical Data Base) are the following: (1) new propellant formulations and chemistry, (2) new ingredients, (3) ballistic effects of the new formulations and ingredients, (4) new processing methods unique to gun propellants, (5) thermochemistry of new ingredients, (6) unique physical and mechanical properties, (7) burning rates of new propellants and small scale closed bomb testing, (8) plasma effects on the propellant, and (9) unique safety and insensitive munitions properties.

  6. Protect Children Instead of Guns, 2002.

    ERIC Educational Resources Information Center

    Children's Defense Fund, Washington, DC.

    Beginning with statistics pertaining to children and gun violence in a single year in the United States, this report details trends in child and youth gun deaths. Tables present information on the following: (1) number of firearms deaths by manner and by race from 1979 to 2000; (2) number of firearms deaths by manner for each state and nationwide,…

  7. Fighting Juvenile Gun Violence. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Sheppard, David; Grant, Heath; Rowe, Wendy; Jacobs, Nancy

    This bulletin describes the Office of Juvenile Justice and Delinquency Prevention's efforts to fight juvenile gun violence. The Office awarded four community demonstration grants to implement "Partnerships To Reduce Juvenile Gun Violence." Partnership goals include increasing the effectiveness of existing strategies by enhancing and coordinating…

  8. Gun Control: The Debate and Public Policy.

    ERIC Educational Resources Information Center

    Watkins, Christine

    1997-01-01

    Provides an overview and background information on the debate over gun control, as well as several teaching ideas. Handouts include a list of related topics drawn from various disciplines (economics, U.S. history), seven arguments for and against gun control, and a set of policy evaluation guidelines. (MJP)

  9. Light gas gun with reduced timing jitter

    DOEpatents

    Laabs, G.W.; Funk, D.J.; Asay, B.W.

    1998-06-09

    Gas gun with reduced timing jitter is disclosed. A gas gun having a prepressurized projectile held in place with a glass rod in compression is described. The glass rod is destroyed with an explosive at a precise time which allows a restraining pin to be moved and free the projectile. 4 figs.

  10. Superconducting 112 MHz QWR electron gun

    SciTech Connect

    Belomestnykh, S.; Ben-Zvi, I.; Boulware, C.H.; Chang, X.; Grimm, T.L.; Rao, T.; Siegel, B.; Skaritka, J.; Than, R.; Winowski, M.; Wu, Q.; Xin, T.; Xue, L.

    2011-07-25

    Brookhaven National Laboratory and Niowave, Inc. have designed and fabricated a superconducting 112 MHz quarter-wave resonator (QWR) electron gun. The first cold test of the QWR cryomodule has been completed at Niowave. The paper describes the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule. Future experiments include studies of different photocathodes and use for the coherent electron cooling proof-of-principle experiment. Two cathode stalk options, one for multi-alkali photocathodes and the other one for a diamond-amplified photocathode, are discussed. A quarter-wave resonator concept of superconducting RF (SRF) electron gun was proposed at BNL for electron cooling hadron beams in RHIC. QWRs can be made sufficiently compact even at low RF frequencies (long wavelengths). The long wavelength allows to produce long electron bunches, thus minimizing space charge effects and enabling high bunch charge. Also, such guns should be suitable for experiments requiring high average current electron beams. A 112 MHz QWR gun was designed, fabricated, and cold-tested in collaboration between BNL and Niowave. This is the lowest frequency SRF gun ever tested successfully. In this paper we describe the gun design and fabrication, present the cold test results, and outline our plans. This gun will also serve as a prototype for a future SRF gun to be used for coherent electron cooling of hadrons in eRHIC.

  11. Light gas gun with reduced timing jitter

    DOEpatents

    Laabs, Gary W.; Funk, David J.; Asay, Blaine W.

    1998-01-01

    Gas gun with reduced timing jitter. A gas gun having a prepressurized projectile held in place with a glass rod in compression is described. The glass rod is destroyed with an explosive at a precise time which allows a restraining pin to be moved and free the projectile.

  12. Youth Homicide and Guns. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Young Americans are killed with guns at rates far higher than young people in other countries and than older Americans, with young, urban African-American males being most at risk. This fact sheet presents data on gun-related homicides among teenagers in the United States. The high rate of youth homicide in the United States is unique in the…

  13. Experiments and Demonstrations with Soldering Guns.

    ERIC Educational Resources Information Center

    Henry, Dennis C.; Danielson, Sarah A.

    1993-01-01

    Discusses the essential electrical characteristics of a particular model of soldering gun. Presents four classroom demonstrations that utilize the soldering gun to test the following geometrics of wire loops as electromagnets: (1) the original tip; (2) a single circular loop; (3) a Helmholtz coil; and (4) the solenoid. (MDH)

  14. Gun shows across a multistate American gun market: observational evidence of the effects of regulatory policies

    PubMed Central

    Wintemute, Garen J

    2007-01-01

    Objective To describe gun shows and assess the impact of increased regulation on characteristics linked to their importance as sources of guns used in crime. Design Cross‐sectional, observational. Subjects Data were collected at a structured sample of 28 gun shows in California, which regulates these events and prohibits undocumented private party gun sales; and in Arizona, Nevada, Texas and Florida—all leading sources of California's crime guns—where these restrictions do not exist. Main outcome measures Size of shows, measured by numbers of gun vendors and people in attendance; number and nature of guns for sale by gun vendors; measures of private party gun sales and illegal surrogate (“straw”) gun purchases. Results Shows in comparison states were larger, but the number of attendees per gun vendor was higher in California. None of these differences was statistically significant. Armed attendees were more common in other states (median 5.7%, interquartile range (IQR) 3.9–10.0%) than in California (median 1.1%, IQR 0.5–2.2%), p = 0.0007. Thirty percent of gun vendors both in California and elsewhere were identifiable as licensed firearm retailers. There were few differences in the types or numbers of guns offered for sale; vendors elsewhere were more likely to sell assault weapons (34.9% and 13.3%, respectively; p = 0.001). Straw purchases were more common in the comparison states (rate ratio 6.6 (95% CI 0.9 to 49.1), p = 0.06). Conclusions California's regulatory policies were associated with a decreased incidence of anonymous, undocumented gun sales and illegal straw purchases at gun shows. No significant adverse effects of these policies were observed. PMID:17567968

  15. Life-threatening nail gun injuries.

    PubMed

    Beaver, A C; Cheatham, M L

    1999-12-01

    The use of pneumatic and explosive cartridge-activated nail guns is common in the construction industry. The ease and speed of nailing these tools afford enhance productivity at the cost of increased potential for traumatic injury. Although extremity injuries are most common, life-threatening injuries to the head, neck, chest, or abdomen and pelvis may occur. During a 20-month period, eight potentially life-threatening nail gun injuries were admitted to a Level I trauma center, including injuries to the brain, eye, neck, heart, lung, and femoral artery. Mechanism of injury included nail ricochet, nail gun misuse due to inadequate training, and successful suicide. Nail guns have significant potential for causing severe debilitating injury and death. These findings indicate a need for improved safety features and user education. The various types of nail guns, their ballistic potential, and techniques for operative management are discussed. PMID:10597056

  16. Sequential injection gas guns for accelerating projectiles

    DOEpatents

    Lacy, Jeffrey M.; Chu, Henry S.; Novascone, Stephen R.

    2011-11-15

    Gas guns and methods for accelerating projectiles through such gas guns are described. More particularly, gas guns having a first injection port located proximate a breech end of a barrel and a second injection port located longitudinally between the first injection port and a muzzle end of the barrel are described. Additionally, modular gas guns that include a plurality of modules are described, wherein each module may include a barrel segment having one or more longitudinally spaced injection ports. Also, methods of accelerating a projectile through a gas gun, such as injecting a first pressurized gas into a barrel through a first injection port to accelerate the projectile and propel the projectile down the barrel past a second injection port and injecting a second pressurized gas into the barrel through the second injection port after passage of the projectile and to further accelerate the projectile are described.

  17. Electron gun jitter effects on beam bunching

    SciTech Connect

    Liu, M. S.; Iqbal, M.

    2014-02-15

    For routine operation of Beijing Electron Positron Collider II (BEPCII) linac, many factors may affect the beam bunching process directly or indirectly. We present the measurements and analyses of the gun timing jitter, gun high voltage jitter, and beam energy at the exit of the standard acceleration section of the linac quantitatively. Almost 80 mV and more than 200 ps of gun high voltage and time jitters have ever been measured, respectively. It was analyzed that the gun timing jitter produced severe effects on beam energy than the gun high voltage jitter, if the timing jitter exceeded 100 ps which eventually deteriorates both the beam performance and the injection rate to the storage ring.

  18. ECR ion source with electron gun

    DOEpatents

    Xie, Z.Q.; Lyneis, C.M.

    1993-10-26

    An Advanced Electron Cyclotron Resonance ion source having an electron gun for introducing electrons into the plasma chamber of the ion source is described. The ion source has a injection enclosure and a plasma chamber tank. The plasma chamber is defined by a plurality of longitudinal magnets. The electron gun injects electrons axially into the plasma chamber such that ionization within the plasma chamber occurs in the presence of the additional electrons produced by the electron gun. The electron gun has a cathode for emitting electrons therefrom which is heated by current supplied from an AC power supply while bias potential is provided by a bias power supply. A concentric inner conductor and outer conductor carry heating current to a carbon chuck and carbon pusher which hold the cathode in place and also heat the cathode. In the Advanced Electron Cyclotron Resonance ion source, the electron gun replaces the conventional first stage used in prior electron cyclotron resonance ion generators. 5 figures.

  19. Rotorcraft noise

    NASA Technical Reports Server (NTRS)

    Huston, R. J. (Compiler)

    1982-01-01

    The establishment of a realistic plan for NASA and the U.S. helicopter industry to develop a design-for-noise methodology, including plans for the identification and development of promising noise reduction technology was discussed. Topics included: noise reduction techniques, scaling laws, empirical noise prediction, psychoacoustics, and methods of developing and validing noise prediction methods.

  20. The Ames Vertical Gun Range

    NASA Technical Reports Server (NTRS)

    Karcz, J. S.; Bowling, D.; Cornelison, C.; Parrish, A.; Perez, A.; Raiche, G.; Wiens, J.-P.

    2016-01-01

    The Ames Vertical Gun Range (AVGR) is a national facility for conducting laboratory- scale investigations of high-speed impact processes. It provides a set of light-gas, powder, and compressed gas guns capable of accelerating projectiles to speeds up to 7 km s(exp -1). The AVGR has a unique capability to vary the angle between the projectile-launch and gravity vectors between 0 and 90 deg. The target resides in a large chamber (diameter approximately 2.5 m) that can be held at vacuum or filled with an experiment-specific atmosphere. The chamber provides a number of viewing ports and feed-throughs for data, power, and fluids. Impacts are observed via high-speed digital cameras along with investigation-specific instrumentation, such as spectrometers. Use of the range is available via grant proposals through any Planetary Science Research Program element of the NASA Research Opportunities in Space and Earth Sciences (ROSES) calls. Exploratory experiments (one to two days) are additionally possible in order to develop a new proposal.

  1. Subterranean well casing perforating gun

    SciTech Connect

    Stout, G. W.; Nelson, J. A.

    1984-10-30

    The invention provides a subterranean well casing perforating gun device which employs shaped explosive charges to perforate the well casing. The device generally defines an outer tubular housing assembly concentrically insertable in the well and defining a vertical axis, cylindrical chamber. A tubular carrier of polygonal cross sectional configuration is insertable in the chamber in concentric relationship to the cylindrical wall of the cylindrical chamber. Each of the faces of the carrier have a plurality of spaced passages therethrough, each passage having a configuration substantially corresponding to the configuration of the polygonal face. A shaped charge container has its cylindrical body insertable in any selected one of the passages and a radial flange on the outer end for abutting the polygonal face portion adjacent the respective passage, thereby limiting the insertion of each of the containers into the selected passage. Selectively disengageable fastening means are operable from the exterior of the carrier for clamping the radial flange against the respective polygonal face and for selective disengagement therefrom from the exterior of the carrier. The invention also contemplates a method of utilization of the carrier and the gun, as well as to incorporation of same into a particular perforating and gravel packing method and apparatus.

  2. A Practical Example Aiding Understanding Momentum in 1D: The Water Gun Experiment

    ERIC Educational Resources Information Center

    MacLeod, Katarin

    2007-01-01

    The law of conservation of momentum is one that students often have difficulties understanding. This experiment allows students to use childhood toys to examine and calculate the muzzle velocity of their favourite water gun by using an air track, a spark timer or data logger and the law of conservation of momentum in a one-dimensional case, a…

  3. Temperature Controller System for Gas Gun Targets

    NASA Astrophysics Data System (ADS)

    Bucholtz, Scott; Sheffield, Stephen

    2005-07-01

    A temperature controller system capable of heating and cooling gas gun targets over the range -75 C to +200 C was designed and tested. The system uses cold nitrogen gas from a liquid nitrogen Dewar for cooling and compressed air for heating. Two gas flow heaters control the gas temperature for both heating and cooling. One heater controls the temperature of the target mounting plate and the other the temperature of a copper tubing coil surrounding the target. Each heater is separately adjustable, so the target material will achieve a uniform temperature throughout its volume. A magnetic gauge with integrated thermocouples was developed to measure the internal temperature of the target. Using this system shock experiments, including equation-of-state measurements and shock initiation of high explosives, can be performed over a range of initial temperatures. Successful tests were completed on Teflon samples. This work was supported by the NNSA Enhanced Surveillance Campaign through contract DE-ACO4-01AL66850.

  4. Gun Violence, Mental Illness, And Laws That Prohibit Gun Possession: Evidence From Two Florida Counties.

    PubMed

    Swanson, Jeffrey W; Easter, Michele M; Robertson, Allison G; Swartz, Marvin S; Alanis-Hirsch, Kelly; Moseley, Daniel; Dion, Charles; Petrila, John

    2016-06-01

    Gun violence kills about ninety people every day in the United States, a toll measured in wasted and ruined lives and with an annual economic price tag exceeding $200 billion. Some policy makers suggest that reforming mental health care systems and improving point-of-purchase background checks to keep guns from mentally disturbed people will address the problem. Epidemiological research shows that serious mental illness contributes little to the risk of interpersonal violence but is a strong factor in suicide, which accounts for most firearm fatalities. Meanwhile, the effectiveness of gun restrictions focused on mental illness remains poorly understood. This article examines gun-related suicide and violent crime in people with serious mental illnesses, and whether legal restrictions on firearm sales to people with a history of mental health adjudication are effective in preventing gun violence. Among the study population in two large Florida counties, we found that 62 percent of violent gun crime arrests and 28 percent of gun suicides involved individuals not legally permitted to have a gun at the time. Suggested policy reforms include enacting risk-based gun removal laws and prohibiting guns from people involuntarily detained in short-term psychiatric hospitalizations. PMID:27269024

  5. Gun Violence, mental health, and Connecticut physicians.

    PubMed

    Dodds, Peter R; Anderson, Caitlyn O; Dodds, Jon H

    2014-01-01

    While there is a public perception that gun violence is associated with mental illness we present evidence that it is a complex public health problem which defies simple characterizations and solutions. Only a small percentage of individuals with mental illness are at risk for extreme violence and they account for only a small percentage of gun-related homicides. Individuals who are at risk for gun violence are difficult to identify and successfully treat. The incidence, and perhaps the demographics, of gun violence vary substantially from state to state. We make a case for Connecticut physicians to study gun violence at the state level. We recommend that Connecticut physicians promote and expand upon the American Academy of Pediatrics' recommendation for creating a "safe home environment. "We suggest that guns be secured in all homes in which there are children. In addition we suggest that guns be voluntarily removed from homes in which there are individuals with a history of violence, threats of violence, depression, drug and/or alcohol abuse, and individuals with major mental illnesses who are not cooperating with therapy. PMID:25745735

  6. Simple light gas guns for hypervelocity studies

    SciTech Connect

    Combs, S.K.; Haselton, H.H.; Milora, S.L.

    1990-01-01

    Two-stage light guns are used extensively in hypervelocity research. The applications of this technology include impact studies and special materials development. Oak Ridge National Laboratory (ORNL) has developed two-stage guns that accelerate small projectiles (4-mm nominal diameter) to velocities of up to {approx}5 km/s. These guns are relatively small and simple (thus, easy to operate), allowing a significant number of test shots to be carried out and data accumulated in a short time. Materials that have been used for projectiles include plastics, frozen isotopes of hydrogen, and lithium hydride. One gun has been used to demonstrate repetitive operation at a rate of 0.7 Hz; and, with a few design improvements, it appears capable of performing at firing frequencies of 1--2 Hz. A schematic of ORNL two-stage device is shown below. Unlike most such devices, no rupture disks are used. Instead, a fast valve (high-flow type) initiates the acceleration process in the first stage. Projectiles can be loaded into the gun breech via the slide mechanism; this action has been automated which allows repetitive firing. Alternatively, the device is equipped with pipe gun'' apparatus in which gas can be frozen in situ in the gun barrel to form the projectile. This equipment operates with high reliability and is well suited for small-scale testing at high velocity. 17 refs., 6 figs., 2 tabs.

  7. Nail-Gun Injuries to the Hand

    PubMed Central

    Pierpont, Yvonne N.; Pappas-Politis, Effie; Naidu, Deepak K.; Salas, R. Emerick; Johnson, Erika L.; Payne, Wyatt G.

    2008-01-01

    Background: The nail gun is a commonly utilized tool in carpentry and construction. When used properly with appropriate safety precautions, it can facilitate production and boost efficiency; however, this powerful tool also has the potential to cause serious injury. The most common site of nail-gun injuries in both industrial and nonoccupational settings is the hand. Materials and Methods: We report on two patients with nail-gun injuries to the hand. A review of the literature and discussion of clinical evaluation and treatment of nail-gun injuries to the hand are presented. Results: Two patients present with soft tissue injuries to the hand with the nail embedded and intact at the injury site. Operative removal of the nail and wound care resulted in successful treatment in both cases. Nail-gun injuries to the hand vary in severity on the basis of the extent of structural damage. Treatment is based on the severity of injury and the presence and location of barbs on the penetrating nail. Conclusion: Healthcare providers must understand and educate patients on the prevention mechanics of nail-gun injuries. Nail-gun injuries to the hand necessitate appropriate evaluation techniques, understanding of surgical management versus nonsurgical management, and awareness of potential pitfalls in treatment. PMID:19079574

  8. Homopolar Gun for Pulsed Spheromak Fusion Reactors II

    SciTech Connect

    Fowler, T

    2004-06-14

    A homopolar gun is discussed that could produce the high currents required for pulsed spheromak fusion reactors even with unit current amplification and open field lines during injection, possible because close coupling between the gun and flux conserver reduces gun losses to acceptable levels. Example parameters are given for a gun compatible with low cost pulsed reactors and for experiments to develop the concept.

  9. Gun Safety Management with Patients at Risk for Suicide

    ERIC Educational Resources Information Center

    Simon, Robert I.

    2007-01-01

    Guns in the home are associated with a five-fold increase in suicide. All patients at risk for suicide must be asked if guns are available at home or easily accessible elsewhere, or if they have intent to buy or purchase a gun. Gun safety management requires a collaborative team approach including the clinician, patient, and designated person…

  10. Alignment Fixtures For Vacuum-Plasma-Spray Gun

    NASA Technical Reports Server (NTRS)

    Woodford, William H.; Mckechnie, Timothy N.; Power, Christopher A.; Daniel, Ronald L., Jr.

    1993-01-01

    Fixtures for alignment of vacuum-plasma-spray guns built. Each fixture designed to fit specific gun and holds small, battery-powered laser on centerline of gun. Laser beam projects small red dot where centerline intersects surface of workpiece to be sprayed. After laser beam positioned on surface of workpiece, fixture removed from gun and spraying proceeds.

  11. Ready, Fire, Aim: The College Campus Gun Fight

    ERIC Educational Resources Information Center

    Birnbaum, Robert

    2013-01-01

    The question of whether guns should be permitted on college and university campuses in the United States reflects the tension between two competing perspectives. America has both a robust gun culture and an equally robust (if less well known) gun-control culture. The gun culture is as American as apple pie: There may be as many as 300 million…

  12. Correlates of Gun Involvement and Aggressiveness among Adolescents.

    ERIC Educational Resources Information Center

    Ding, Cody S.; Nelsen, Edward A.; Lassonde, Cynthia T.

    2002-01-01

    Investigated adolescents' aggressiveness in relation to their experiences, beliefs, and attitudes concerning gun use, also noting family composition, relationships with parents, and emotionality as correlates of gun involvement and aggression. Student surveys indicated links between gun ownership and recreational use, beliefs about gun use, and…

  13. Establishing reliable good initial quantum efficiency and in-situ laser cleaning for the copper cathodes in the RF gun

    NASA Astrophysics Data System (ADS)

    Zhou, F.; Sheppard, J. C.; Vecchione, T.; Jongewaard, E.; Brachmann, A.; Corbett, J.; Gilevich, S.; Weathersby, S.

    2015-05-01

    Establishing good initial quantum efficiency (QE) and reliable in-situ cleaning for copper cathode in the RF gun is of critical importance for the RF gun operations. Recent studies on the SLAC RF gun test bed indicated that the pre-cleaning (plasma cleaning) in the test chamber followed by copper cathode exposure to air for cathode change leads to a very low initial QE in the RF gun, and also demonstrated that without the pre-cleaning good initial QE >4×10-5 can be routinely achieved in the RF gun with the cathodes of QE <1×10-7 measured in the test chamber. QE can decay over the time in the RF gun. The in-situ laser cleaning technique for copper cathodes in the RF gun is established and refined in comparison to previous cleaning at the linac coherent light source, resulting in an improved QE and emittance evolutions. The physics of the laser cleaning process is discussed. It is believed that the reflectivity change is one of the major factors for the QE boost with the laser cleaning.

  14. Studies of electronic noise in gyroklystrons

    NASA Astrophysics Data System (ADS)

    Calame, J. P.; Danly, B. G.; Garven, M.; Levush, B.

    2000-05-01

    Direct measurements of phase noise in a four-cavity, 35 GHz gyroklystron producing 50 μs pulses of 175-210 kW output power with 50-53 dB saturated gain are presented. The measurements were performed at a 10.7 MHz frequency offset from the carrier, where the noise is expected to be dominated by shot noise and where the extrinsic noise from the electron gun's pulsed power supply is manageable. At an operating point with 70 kV beam voltage, 9 A beam current, and a beam velocity ratio of 1.3, a phase noise of -149±1 dBc/Hz was measured during the production of 180 kW output power at 50 dB gain. At a higher beam current of 10 A, the measured phase noise was -146±1 dBc/Hz during production of a 200 kW output power carrier with 53 dB gain. The directly measured phase noise levels were generally within 2-3 dB of the values expected on the basis of carrier-free noise temperature measurements. Overall, the measured gyroklystron noise levels are similar to those of conventional klystrons. Also presented are analytic calculations of the growth rates expected for electrostatic cyclotron instabilities in the region between the electron gun and the input cavity in a previous three-cavity gyroklystron. Very modest perpendicular velocity spreads (rms greater than 2%) are found to completely suppress such noise growth. This lack of significant noise growth above that of bare shot noise is in agreement with experimental results.

  15. A Two Frequency Thermionic Cathode Electron Gun

    NASA Astrophysics Data System (ADS)

    Edelen, Jon; Biedron, Sandra; Harris, John; Lewellen, John; Milton, Stephen

    2014-03-01

    When an un-gated thermionic cathode is operated in an RF gun, some fraction of the emitted electrons will return to the cathode due to the change in sign of the electric field in the gun. This back-bombardment current causes heating of the cathode, and this reduces the ability of the cathode heater to control the bunch charge. In this paper, we investigate the use of a two frequency TM010 / TM020 electron gun to mitigate this effect. Simulations revealed that for a 100-pC bunch charge operating at 10MV/m gradient the harmonic field produced a 63% reduction in the back-bombardment power.

  16. SSRL photocathode RF gun test stand

    SciTech Connect

    Hernandez, M.; Baltay, M.; Boyce, A.

    1995-12-31

    A photocathode RF gun test stand designed for the production and study of high brightness electron beams will be constructed at SSRL. The beam will be generated from a laser driven third generation photocathode RF gun being developed in collaboration with BNL, LBL, and UCLA. The 3-5 [MeV] beam from the gun will be accelerated using a SLAC three meter S-band accelerator section, in order to achieve the desired low emittance beam, emittance compensation with solenoidal focusing will be employed.

  17. Advances in DC photocathode electron guns

    SciTech Connect

    Bruce M. Dunham; P. Heartmann; Reza Kazimi; Hongxiu Liu; B. M. Poelker; J. S. Price; P. M. Rutt; W. J. Schneider; Charles K. Sinclair

    1998-07-01

    At Jefferson Lab, a DC photoemission gun using GaAs and GaAs-like cathodes provides a source of polarized electrons for the main accelerator. The gun is required to produce high average current with long operational lifetimes and high system throughout. Recent work has shown that careful control of the parameters affecting cathode lifetime lead to dramatic improvements in source operation. These conditions include vacuum and the related effect of ion backbombardment, and precise control of all of the electrons emitted from the cathode. In this paper, the authors will review recent results and discuss implications for future photocathode guns.

  18. Evaluation of Smart Gun Technologies preliminary report

    SciTech Connect

    Weiss, D.R.

    1996-01-01

    The Smart Gun Technology Project has a goal to eliminate the capability of an unauthorized user from firing a law enforcement officer`s firearm by implementing {open_quote}smart{close_quote} technologies. Smart technologies are those that can in some manner identify an officer. This report will identify, describe, and grade various technologies as compared to the requirements that were obtained from officers. This report does not make a final recommendation for a smart gun technology, nor does it give the complete design of a smart gun system.

  19. Performance of the Brookhaven photocathode rf gun

    SciTech Connect

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, J.; Fisher, A.S.; Gallardo, J.; Ingold, G.; Kirk, H.G.; Leung, K.P.; Malone, R.; Pogorelsky, I.; Srinivasan-Rao, T.; Rogers, J.; Tsang, T.; Sheehan, J.; Ulc, S.; Woodle, M.; Xie, J.; Zhang, R.S.; Lin, L.Y.; McDonald, K.T.; Russell, D.P.; Hung, C.M.; Wang, X.J.

    1991-12-31

    The Brookhaven Accelerator Test Facility (ATF) uses a photocathode rf gun to provide a high-brightness electron beam intended for FEL and laser-acceleration experiments. The rf gun consists of 1{1/2} cells driven at 2856 MHz in {pi}-mode with a maximum cathode field of 100 MV/m. To achieve long lifetimes, the photocathode development concentrates on robust metals such as copper, yttrium and samarium. We illuminate these cathodes with a 10-ps, frequency-quadrupled Nd:YAG laser. We describe the initial operation of the gun, including measurements of transverse and longitudinal emittance, quantum efficiencies, and peak current. The results are compared to models.

  20. Performance of the Brookhaven photocathode rf gun

    SciTech Connect

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, J.; Fisher, A.S.; Gallardo, J.; Ingold, G.; Kirk, H.G.; Leung, K.P.; Malone, R.; Pogorelsky, I.; Srinivasan-Rao, T.; Rogers, J.; Tsang, T.; Sheehan, J.; Ulc, S.; Woodle, M.; Xie, J.; Zhang, R.S. ); Lin, L.Y. . Dept. of Applied Physics); McDonald, K.T.; Russell, D.P. (Pr

    1991-01-01

    The Brookhaven Accelerator Test Facility (ATF) uses a photocathode rf gun to provide a high-brightness electron beam intended for FEL and laser-acceleration experiments. The rf gun consists of 1{1/2} cells driven at 2856 MHz in {pi}-mode with a maximum cathode field of 100 MV/m. To achieve long lifetimes, the photocathode development concentrates on robust metals such as copper, yttrium and samarium. We illuminate these cathodes with a 10-ps, frequency-quadrupled Nd:YAG laser. We describe the initial operation of the gun, including measurements of transverse and longitudinal emittance, quantum efficiencies, and peak current. The results are compared to models.

  1. "Is there a gun in the home?" Assessing the risks of gun ownership in older adults.

    PubMed

    Pinholt, Ellen M; Mitchell, Joshua D; Butler, Jane H; Kumar, Harjinder

    2014-06-01

    An important ethical and safety concern that geriatricians, primary care providers, and home health professionals need to address is gun ownership by elderly adults. Those aged 65 and older now have the highest rate of gun ownership in America, and they also have a high prevalence of depression and suicide. Dementia can add additional layers of risk. Even older gun owners who are otherwise intellectually intact may benefit from information about gun safety with the increasing numbers of children being cared for by grandparents. Health professionals should ask patients, "Is there a gun in the home?" in the clinic and during home visits. Healthcare professionals must have knowledge and skills to address safe gun ownership in elderly adults. The 5 L's (Locked, Loaded, Little children, feeling Low, Learned owner) will assist professionals in addressing all aspects of safe ownership. PMID:24898055

  2. 32 CFR 989.32 - Noise.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ANALYSIS PROCESS (EIAP) § 989.32 Noise. Aircraft noise data files used for analysis during EIAP will be... System for Aircraft Noise for military training routes and military operating areas. Guidance on... EIAP land use analysis relating to aircraft noise impacts originating from air installations...

  3. Effects of undercover police stings of gun dealers on the supply of new guns to criminals

    PubMed Central

    Webster, D W; Bulzacchelli, M T; Zeoli, A M; Vernick, J S

    2006-01-01

    Objective To assess the effects of undercover police stings and lawsuits against gun dealers suspected of facilitating illegal gun sales in three US cities (Chicago, Detroit, Gary) on the flow of new firearms to criminals. Methods An interrupted time series design and negative binomial regression analyses were used to test for temporal change in the recovery of guns used in crimes within one year of retail sale in both intervention and comparison cities. Results The stings were associated with an abrupt 46.4% reduction in the flow of new guns to criminals in Chicago (95% confidence interval, −58.6% to −30.5%), and with a gradual reduction in new crime guns recovered in Detroit. There was no significant change associated with the stings in Gary, and no change in comparison cities that was coincident with the stings in Chicago and Detroit. Conclusions The announcement of police stings and lawsuits against suspect gun dealers appeared to have reduced the supply of new guns to criminals in Chicago significantly, and may have contributed to beneficial effects in Detroit. Given the important role that gun stores play in supplying guns to criminals in the US, further efforts of this type are warranted and should be evaluated. PMID:16887943

  4. Separating batterers and guns: a review and analysis of gun removal laws in 50 States.

    PubMed

    Frattaroli, Shannon; Vernick, Jon S

    2006-06-01

    Firearms play an important role in lethal domestic violence incidents. The authors review state laws regarding two policies to separate batterers from firearms: laws authorizing police to remove firearms when responding to a domestic violence complaint ("police gun removal laws") and laws authorizing courts to order guns removed from batterers through a protective order ("court-ordered removal laws"). As of April 2004, 18 states had police gun removal laws; 16 states had court-ordered removal laws. The authors examine relevant characteristics of the laws and recommend that these laws be mandatory, apply to all guns and ammunition possessed by an abuser, and include clear procedures to enhance implementation. PMID:16679498

  5. Noise prevention

    NASA Astrophysics Data System (ADS)

    Methods for noise abatement are discussed. Noise nuisance, types of noise (continuous, fluctuating, intermittent, pulsed), and types of noise abatement (absorption, vibration damping, isolation) are defined. Rockwool panels, industrial ceiling panels, baffles, acoustic foam panels, vibration dampers, acoustic mats, sandwich panels, isolating cabins and walls, ear protectors, and curtains are presented.

  6. Circuit Model for Gun Driven Spheromaks

    SciTech Connect

    Thomassen, K I

    2000-07-14

    In this note we derive circuit equations for sustained spheromaks, in the phase after a spheromak is detached from the gun and sustained in a flux conserver. The impedance of the spheromak during the formation and ''bubble burst'' phase has been discussed by Barnes et. al. We assume here that the spheromak is formed and helicity is being delivered to it from the gun, currents are above the threshold current, and the {lambda}-gradients are outward ({lambda} decreasing inward). We follow an open field line that begins and ends at the gun electrodes, encircling the closed flux surfaces of the spheromak, and apply power and helicity balance equations for this gun-driven system. In addition to these equations one will need to know the initial conditions (currents, stored energies) after the ''bubble burst'' in order to project forward in time.

  7. The electric rail gun for space propulsion

    NASA Technical Reports Server (NTRS)

    Bauer, D. P.; Barber, J. P.; Vahlberg, C. J.

    1981-01-01

    An analytic feasibility investigation of an electric propulsion concept for space application is described. In this concept, quasistatic thrust due to inertial reaction to repetitively accelerated pellets by an electric rail gun is used to propel a spacecraft. The study encompasses the major subsystems required in an electric rail gun propulsion system. The mass, performance, and configuration of each subsystem are described. Based on an analytic model of the system mass and performance, the electric rail gun mission performance as a reusable orbital transfer vehicle (OTV) is analyzed and compared to a 30 cm ion thruster system (BIMOD) and a chemical propulsion system (IUS) for payloads with masses of 1150 kg and 2300 kg. For system power levels in the range from 25 kW(e) to 100 kW(e) an electric rail gun OTV is more attractive than a BIMOD system for low Earth orbit to geosynchronous orbit transfer durations in the range from 20 to 120 days.

  8. Arc-driven rail gun research

    NASA Technical Reports Server (NTRS)

    Ray, P. K.

    1984-01-01

    The equations describing the performance of an inductively-driven rail gun are analyzed numerically. Friction between the projectile and rails is included through an empirical formulation. The equations are applied to the experiment of Rashleigh and Marshall to obtain an estimate of energy distribution in rail guns as a function of time. The effect of frictional heat dissipation on the bore of the gun is calculated. The mechanism of plasma and projectile acceleration in a dc rail gun is described from a microscopic point of view through the establishment of the Hall field. The plasma conductivity is shown to be a tensor indicating that there is a small component of current parallel to the direction of acceleration. The plasma characteristics are evaluated as a function of plasma mass through a simple fluid mechanical analysis of the plasma. By equating the energy dissipated in the plasma with the radiation heat loss, the properties of the plasma are determined.

  9. Direct launch using the electric rail gun

    NASA Technical Reports Server (NTRS)

    Barber, J. P.

    1983-01-01

    The concept explored involves using a large single stage electric rail gun to achieve orbital velocities. Exit aerodynamics, launch package design and size, interior ballistics, system and component sizing and design concepts are treated. Technology development status and development requirements are identified and described. The expense of placing payloads in Earth orbit using conventional chemical rockets is considerable. Chemical rockets are very inefficient in converting chemical energy into payload kinetic energy. A rocket motor is relatively expensive and is usually expended on each launch. In addition specialized and expensive forms of fuel are required. Gun launching payloads directly to orbit from the Earth's surface is a possible alternative. Guns are much more energy efficient than rockets. The high capital cost of the gun installation can be recovered by reusing it over and over again. Finally, relatively inexpensive fuel and large quantities of energy are readily available to a fixed installation on the Earth's surface.

  10. Arc Plasma Gun With Coaxial Powder Feed

    NASA Technical Reports Server (NTRS)

    Zaplatynsky, Isidor

    1988-01-01

    Redesigned plasma gun provides improved metallic and ceramic coatings. Particles injected directly through coaxial bore in cathode into central region of plasma jet. Introduced into hotter and faster region of plasma jet.

  11. Lightweight, High-Current Welding Gun

    NASA Technical Reports Server (NTRS)

    Starck, Thomas F.; Brennan, Andrew D.

    1989-01-01

    Lighweight resistance-welding, hand-held gun supplies alternating or direct current over range of 600 to 4,000 A and applies forces from 40 to 60 lb during welding. Used to weld metal sheets in multilayered stacks.

  12. Toroid Joining Gun For Fittings And Couplings

    NASA Technical Reports Server (NTRS)

    Fox, Robert L.; Swaim, Robert J.; Johnson, Samuel D.; Buckley, John D.; Copeland, Carl E.; Coultrip, Robert H.; Johnston, David F.; Phillips, William M.

    1992-01-01

    Hand-held gun used to join metal heat-to-shrink couplings. Uses magnetic induction (eddy currents) to produce heat in metal coupling, and thermocouple to measure temperature and signals end of process. Gun, called "toroid joining gun" concentrates high levels of heat in localized areas. Reconfigured for use on metal heat-to-shrink fitting and coupling applications. Provides rapid heating, operates on low power, lightweight and portable. Safe for use around aircraft fuel and has no detrimental effects on surrounding surfaces or objects. Reliable in any environment and under all weather conditions. Gun logical device for taking full advantage of capabilities of new metal heat-to-shrink couplings and fittings.

  13. Combustion noise

    NASA Technical Reports Server (NTRS)

    Strahle, W. C.

    1977-01-01

    A review of the subject of combustion generated noise is presented. Combustion noise is an important noise source in industrial furnaces and process heaters, turbopropulsion and gas turbine systems, flaring operations, Diesel engines, and rocket engines. The state-of-the-art in combustion noise importance, understanding, prediction and scaling is presented for these systems. The fundamentals and available theories of combustion noise are given. Controversies in the field are discussed and recommendations for future research are made.

  14. Conference on electromagnetic guns and launchers, 1980

    SciTech Connect

    Anon

    1982-01-01

    Proceedings includes 31 papers dealing with the physical principles and engineering technology associated with the development of electromagnetic propulsion, with emphasis on its use for guns, launchers as well as other military equipment. Topics covered include: rail guns, projectiles, mass accelerators, electric motors and generators, nuclear reactors, superconducting devices, plasma acceleration and confinement, traveling magnetic waves, aerospace propulsion, space shuttles, homopolar generators, fusion reactors, tokamaks, impact fusion, and electric power generation. 14 papers are abstracted and indexed separately.

  15. Modifications Of A Commercial Spray Gun

    NASA Technical Reports Server (NTRS)

    Allen, Peter B.

    1993-01-01

    Commercial spray gun modified to increase spray rate and make sprayed coats more nearly uniform. Consists of gun head and pneumatic actuator. Actuator opens valves for two chemical components, called "A" and "B," that react to produce foam. Components flow through orifices, into mixing chamber in head. Mixture then flows through control orifice to spray tip. New spray tip tapered to reduce area available for accumulation of foam and makes tip easier to clean.

  16. NPS Gas Gun for Planar Impact Studies

    NASA Astrophysics Data System (ADS)

    Cheong Ho, Chien; Hixson, Robert

    2009-11-01

    The Naval Postgraduate School (NPS) commissioned a Gas Gun for shock wave studies on 9^th October 2009, by performing the first experiment. The Gas Gun is the key element of NPS Shock Wave Research Program within the Physics Department, where well-characterized planar impacts are essential for obtaining high quality data, to characterize a solid material. This first experiment was very successful, and returned key data on the quality of the impact conditions created. The Gas Gun is designed by SANDIA NATIONAL LABORATORIES, and the NPS spent twelve months fabricating the components of the Gas Gun and six months assembling the Gas Gun. Three inch projectile are launched at velocities up to 0.5 km/s, creating high pressure and temperature states that can be used to characterize the fundamental response of relevant materials to dynamic loading. The projectile is launched from a `wrap around' gas breech where helium gas is pressurized to relatively low pressure. This gas is used to accelerate the projectile down a 3m barrel. Upon impact, the speed of the projectile and the flatness of the impact is measured, via a stepped circular pin array circuit. The next stage of development for the Gas Gun is to integrate a Velocity Interferometer System for Any Reflector (VISAR). The VISAR sees all the waves that flow through the target plate as a result of the impact. This is a key diagnostic for determining material properties under dynamic loading conditions.

  17. Blast noise impacts on sleep

    NASA Astrophysics Data System (ADS)

    Nykaza, Edward T.; Pater, Larry L.

    2005-04-01

    Firing large guns during the hours of darkness is essential to combat readiness for the military. At the same time most people are particularly sensitive to noise when sleeping or trying to fall asleep. Laboratory studies done by Griefahn [J. Sound and Vib. 128, 109-119 (1989)] and Luz [see Luz et al., ERDC/CERL, TR-04-26 (2004)] suggest that a time period at night may exist where people are more tolerant to large weapon impulse noise (blast noise) and therefore, are less likely to be awakened from noise events. In the fall of 2004, a field study was conducted around a military installation to determine if such a time period(s) exists. Noise monitors were set up inside and outside of residents homes to record noise levels from live military training activities and actimeters were worn by participants sleeping their natural environment to measure sleep disturbance and awakening. The method and results of this study will be presented. [Work supported by US Army Engineer Research and Development Center CERL.

  18. Separating Batterers and Guns: A Review and Analysis of Gun Removal Laws in 50 States

    ERIC Educational Resources Information Center

    Frattaroli, Shannon; Vernick, Jon S.

    2006-01-01

    Firearms play an important role in lethal domestic violence incidents. The authors review state laws regarding two policies to separate batterers from firearms: laws authorizing police to remove firearms when responding to a domestic violence complaint ("police gun removal laws") and laws authorizing courts to order guns removed from batterers…

  19. Gun Carrying by High School Students in Boston, MA: Does Overestimation of Peer Gun Carrying Matter?

    ERIC Educational Resources Information Center

    Hemenway, David; Vriniotis, Mary; Johnson, Renee M.; Miller, Matthew; Azrael, Deborah

    2011-01-01

    This paper investigates: (1) whether high school students overestimate gun carrying by their peers, and (2) whether those students who overestimate peer gun carrying are more likely to carry firearms. Data come from a randomly sampled survey conducted in 2008 of over 1700 high school students in Boston, MA. Over 5% of students reported carrying a…

  20. The supply and demand for guns to juveniles: Oakland's gun tracing project.

    PubMed

    Calhoun, Deane; Dodge, Andrea Craig; Journel, Coraline S; Zahnd, Elaine

    2005-12-01

    In response to Oakland, California's high level of gun violence affecting young people, the East Oakland Partnership to Reduce Juvenile Gun Violence, a citywide collaboration, was formed in 1997. In 1999, the Partnership established the Oakland Gun Tracing Project to develop evidence-based policy recommendations aimed at reducing the supply of and demand for gun acquisition among urban youth. The advocacy project involved gathering, analyzing, and using police record and gun sale/registration data to inform policy and practice. Such data were collected for all gun crimes committed in Oakland, California between 1998 and 1999 in which a juvenile was either the suspect or the victim. The 213 cases involved 263 juveniles of which 170 were suspects/perpetrators and 93 were victims. Suspects as well as victims were predominantly male and African American. The 213 cases involved 132 recovered guns. Only 55% of the cases were traced to a federally licensed dealer. Three-quarters of the guns were purchased near Oakland, California. Successful traces, defined as the ability to identify federally licensed dealers and initial purchasers, were completed on only 52 of the 132 guns, demonstrating systemic tracing difficulties. Data gathered for the project was used to advocate for numerous policy changes. Recommended policy strategies include initiating a comprehensive gun tracing program so police can track all secondary sales, new laws requiring federal handgun registration which would track ownership changes, required reporting of stolen firearms, and providing effective intervention services to all juveniles the first time they enter the criminal justice system. PMID:16269532

  1. Community noise

    NASA Technical Reports Server (NTRS)

    Bragdon, C. R.

    1982-01-01

    Airport and community land use planning as they relate to airport noise reduction are discussed. Legislation, community relations, and the physiological effect of airport noise are considered. Noise at the Logan, Los Angeles, and Minneapolis/St. Paul airports is discussed.

  2. A high-brightness thermionic microwave electron gun

    SciTech Connect

    Borland, M.

    1991-02-01

    In a collaborative effort by SSRL, AET Associates, and Varian Associates, a high-brightness microwave electron gun using a thermionic cathode has been designed, built, tested, and installed for use with the SSRL 150 MeV linear accelerator. This thesis discusses the physics behind the design and operation of the gun and associated systems, presenting predictions and experimental tests of the gun's performance. The microwave gun concept is of increasing interest due to its promise of providing higher-current, lower-emittance electron beams than possible from conventional, DC gun technology. In a DC guns, accelerating gradients are less than 8 MV/m, while those in a microwave gun can exceed 100 MV/m, providing much more rapid initial acceleration, thereby reducing the deleterious effects of space-charge. Microwave guns produce higher momentum beams than DC guns, thus lessening space-charge effects during subsequent beam transport. Typical DC guns produce kinetic energies of 80--400 KeV, compared to 2--3 MeV for the SSRL microwave gun. State-of-the-art'' microwave gun designs employ laser-driven photocathodes, providing excellent performance but with greater complexity and monetary costs. A thermionic microwave gun with a magnetic bunching system is comparable in cost and complexity to a conventional system, but provides performance that is orders of magnitude better. Simulations of the SSRL microwave gun predict a normalized RMS emittance at the gun exist of < 10 {pi} {center dot} m{sub e}c {center dot} {mu}m for a beam consisting of approximately 50% of the particles emitted from the gun, and having a momentum spread {plus minus}10%. These emittances are for up to 5 {times} 10{sup 9}e{sup {minus}} per bunch. Chromatic aberrations in the transport line between the gun and linear accelerator increase this to typically < 30 {pi} {center dot} m{sub e} {center dot} {mu}m.

  3. Development of plasma cathode electron guns

    NASA Astrophysics Data System (ADS)

    Oks, Efim M.; Schanin, Peter M.

    1999-05-01

    The status of experimental research and ongoing development of plasma cathode electron guns in recent years is reviewed, including some novel upgrades and applications to various technological fields. The attractiveness of this kind of e-gun is due to its capability of creating high current, broad or focused beams, both in pulsed and steady-state modes of operation. An important characteristic of the plasma cathode electron gun is the absence of a thermionic cathode, a feature which leads to long lifetime and reliable operation even in the presence of aggressive background gas media and at fore-vacuum gas pressure ranges such as achieved by mechanical pumps. Depending on the required beam parameters, different kinds of plasma discharge systems can be used in plasma cathode electron guns, such as vacuum arcs, constricted gaseous arcs, hollow cathode glows, and two kinds of discharges in crossed E×B fields: Penning and magnetron. At the present time, plasma cathode electron guns provide beams with transverse dimension from fractional millimeter up to about one meter, beam current from microamperes to kiloamperes, beam current density up to about 100 A/cm2, pulse duration from nanoseconds to dc, and electron energy from several keV to hundreds of keV. Applications include electron beam melting and welding, surface treatment, plasma chemistry, radiation technologies, laser pumping, microwave generation, and more.

  4. Electron gun system for NSC KIPT linac

    NASA Astrophysics Data System (ADS)

    Zhou, Zu-Sheng; He, Da-Yong; Chi, Yun-Long

    2014-06-01

    In the NSC KIPT linac, a neutron source based on a subcritical assembly driven by a 100 MeV/100 kW electron linear accelerator is under design and development. The linear accelerator needs a new high current electron gun. In this paper, the physical design, mechanical fabrication and beam test of this new electron gun are described. The emission current is designed to be higher than 2 A for the pulse width of 3 μs with repetition rate of 50 Hz. The gun will operate with a DC high voltage power supply that can provide a high voltage up to 150 kV. Computer simulations and optimizations have been carried out in the design stage, including the gun geometry and beam transport line. The test results of high voltage conditioning and beam test are presented. The operation status of the electron gun system is also included. The basic test results show that the design, manufacture, and operation of the new electron system are basically successful.

  5. ECR ion source with electron gun

    DOEpatents

    Xie, Zu Q.; Lyneis, Claude M.

    1993-01-01

    An Advanced Electron Cyclotron Resonance ion source (10) having an electron gun (52) for introducing electrons into the plasma chamber (18) of the ion source (10). The ion source (10) has a injection enclosure (12) and a plasma chamber tank (14). The plasma chamber (18) is defined by a plurality of longitudinal magnets (16). The electron gun (52) injects electrons axially into the plasma chamber (18) such that ionization within the plasma chamber (18) occurs in the presence of the additional electrons produced by the electron gun (52). The electron gun (52) has a cathode (116) for emitting electrons therefrom which is heated by current supplied from an AC power supply (96) while bias potential is provided by a bias power supply (118). A concentric inner conductor (60) and Outer conductor (62) carry heating current to a carbon chuck (104) and carbon pusher (114) Which hold the cathode (116) in place and also heat the cathode (16). In the Advanced Electron Cyclotron Resonance ion source (10), the electron gun (52) replaces the conventional first stage used in prior art electron cyclotron resonance ion generators.

  6. Influence of the Spray Gun Type on Microstructure and Properties of HVAF Sprayed Fe-Based Corrosion Resistant Coatings

    NASA Astrophysics Data System (ADS)

    Milanti, A.; Koivuluoto, H.; Vuoristo, P.

    2015-10-01

    The aim of this study is to evaluate the microstructural details and corrosion properties of novel Fe-based coatings prepared using two different generations of HVAF spray guns. These two generations of HVAF guns are Activated Combustion HVAF (AC-HVAF, 2nd generation) M2 gun and Supersonic Air Fuel HVAF (SAF, 3rd generation) M3 gun. Structural details were analysed using x-ray diffractometry and field-emission scanning electron microscope. Higher denseness with homogeneous microstructure was achieved for Fe-based coating deposited by the M3 process. Such coatings exhibit higher particle deformation and lower oxide content compared to coatings manufactured with M2 gun. Corrosion properties were studied by open-cell potential measurements and electrochemical impedance spectroscopy. The lower porosity and higher interlamellar cohesion of coating manufactured with M3 gun prevent the electrolyte from penetrating through the coating and arriving to the substrate, enhancing the overall corrosion resistance. This can be explained by the improved microstructures and coating performance.

  7. Rotor noise

    NASA Technical Reports Server (NTRS)

    Schmitz, F. H.

    1991-01-01

    The physical characteristics and sources of rotorcraft noise as they exist today are presented. Emphasis is on helicopter-like vehicles, that is, on rotorcraft in nonaxial flight. The mechanisms of rotor noise are reviewed in a simple physical manner for the most dominant sources of rotorcraft noise. With simple models, the characteristic time- and frequency-domain features of these noise sources are presented for idealized cases. Full-scale data on several rotorcraft are then reviewed to allow for the easy identification of the type and extent of the radiating noise. Methods and limitations of using scaled models to test for several noise sources are subsequently presented. Theoretical prediction methods are then discussed and compared with experimental data taken under very controlled conditions. Finally, some promising noise reduction technology is reviewed.

  8. [Comparison of wound morphology following gunshots by machine guns and sub-machine guns].

    PubMed

    Grellner, W; Madea, B

    1999-01-01

    Automatic weapons such as machine guns and submachine guns are found in the German-speaking region only in special army and police units and appear accordingly rarely in homicides, suicides and accidents. In the following, the findings in two cases of death with the use of machine and submachine guns are presented. The first case was a fatal accident during shooting on a training area (current machine gun of the German army, calibre 7.62 x 51 mm), the second case was a killing during a physical conflict (submachine gun MP 40 from World War II, calibre 9 x 19 mm). In the case with the machine gun autopsy disclosed typical entry holes corresponding to the calibre, but unusually large exit wounds with tissue bridges in the wound ground, measuring 4 x 2.5 cm in diameter. By contrast, the second case (submachine gun) showed "normal" entry and exit wounds. The differences are mainly caused by deviating ballistic data of the ammunition used. They are discussed against the background of literature on wound ballistics. PMID:10198694

  9. 13. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), VIEW NORTH AT SOUTH END OF BUILDING. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  10. Community noise levels in Patras, Greece

    SciTech Connect

    Stathis, T.C.

    1981-02-01

    In the city of Patras (Greece), noise measurements were made for the purposes of determining the present noise-pollution levels and the reaction of the people to them. Noise pollution is ranked second in order after air pollution, and traffic was the principal noise pollutant. The mean noise levels, in 25 monitorig stations throughout the city, were found to be high and definitely unacceptable. For three representative locations, corresponding to high, medium, and low traffic volume, various statistical noise descriptors were used, together with the other measurements, to estimate the noise environment of the entire city.

  11. The Real Costs of Gun Violence

    SciTech Connect

    Cook, Philip J.

    2001-03-14

    I will report some of the results in my new book, 'Gun Violence: The Real Costs' (Oxford University Press, 2000; with Jens Ludwig). The problem of gun violence is usually summarized by statistics on deaths and injuries. Those statistics tell only part of the story. All of us bear some of the burden of gun violence, at least in the form of higher taxes and waiting to go through the airport security checks. But that's just the beginning. The extraordinary reductions in lethal violence that occurred during the 1990s help account for rising property values and urban renewal; further reductions are possible and would do still more to enhance the average standard of living. This talk will explain why the economic perspective provides a fresh, useful point of view on violence, and will discuss the technique used to arrive at an estimate of the magnitude of the burden.

  12. Electromagnetic theta gun and tubular projectiles

    SciTech Connect

    Burgess, T.J.; Cnare, E.C.; Oberkampf, W.L.; Beard, S.G.; Cowan, M.

    1980-12-01

    Unlike the better known rail gun, the theta gun applies the propelling force along the length of its projectile. This is shown to allow much greater acceleration of high fineness ratio projectiles for a given barrel pressure, allowing much shorter barrels for military applications. A computer code which simulates performance of the theta gun is described and experimental results from a few simple, low energy experiments show close agreement with code predictions. Trajectories and aerodynamic heating for three candidate military projectiles are calculated for vertical and horizontal atmospheric launches where initial velocity is as high as 3 km/s. The calculations indicate that in some cases a thin layer of heatshield (ablator) will be required to control projectile heating.

  13. An analysis of electron guns for welding

    NASA Astrophysics Data System (ADS)

    Sabchevski, S. P.; Mladenov, G. M.; Wojcicki, S.; Dabek, J.

    1996-06-01

    Results from numerical experiments and direct measurements for the analysis of an axially symmetric triode electron gun with thermionic cathode for electron beam welding are presented and discussed. Computer simulation is carried out using the new version of the GUN-EBT software package. The self-consistent model takes into account the energy spectrum of emitted electrons and formation of a potential minimum in front of the cathode. The method underlying the investigation incorporates not only the commonly used trajectory analysis (ray tracing) but also an analysis in the phase space (phase analysis) which allows the emittance of the beams to be evaluated. It is demonstrated that computer simulation of beam formation provides ample information for the assessment both of the quality of generated beams and operational performance of the guns.

  14. Pulser for the Tevatron electron lens gun

    SciTech Connect

    Iouri Terechkine et al.

    2004-05-18

    To compensate for beam-beam interaction in Tevatron, an ''electron lens'' is considered to be an effective instrument. When a bunch of electrons with energy in the range (10-16) kV is overlapping with a bunch of antiprotons, the resulting focusing force for antiprotons can be adjusted by changing the electron beam current and by profiling its radial distribution. There exist several scenarios of how the system must function. According to one of them, an electron gun that supplies electrons must be fed by voltage pulses that follow with the frequency of antiproton bunches circulating in the Tevatron, which is about 2.5 MHz. To provide focusing tailored for each individual antiproton bunch, a modulator of the gun (pulser) must allow pulse-to-pulse voltage change. This report will cover main approaches to a design of a pulser for use with the gun of the Tevatron Electron Lens.

  15. Secondary emission electron gun using external primaries

    DOEpatents

    Srinivasan-Rao, Triveni; Ben-Zvi, Ilan; Kewisch, Jorg; Chang, Xiangyun

    2007-06-05

    An electron gun for generating an electron beam is provided, which includes a secondary emitter. The secondary emitter includes a non-contaminating negative-electron-affinity (NEA) material and emitting surface. The gun includes an accelerating region which accelerates the secondaries from the emitting surface. The secondaries are emitted in response to a primary beam generated external to the accelerating region. The accelerating region may include a superconducting radio frequency (RF) cavity, and the gun may be operated in a continuous wave (CW) mode. The secondary emitter includes hydrogenated diamond. A uniform electrically conductive layer is superposed on the emitter to replenish the extracted current, preventing charging of the emitter. An encapsulated secondary emission enhanced cathode device, useful in a superconducting RF cavity, includes a housing for maintaining vacuum, a cathode, e.g., a photocathode, and the non-contaminating NEA secondary emitter with the uniform electrically conductive layer superposed thereon.

  16. Secondary emission electron gun using external primaries

    DOEpatents

    Srinivasan-Rao, Triveni; Ben-Zvi, Ilan

    2009-10-13

    An electron gun for generating an electron beam is provided, which includes a secondary emitter. The secondary emitter includes a non-contaminating negative-electron-affinity (NEA) material and emitting surface. The gun includes an accelerating region which accelerates the secondaries from the emitting surface. The secondaries are emitted in response to a primary beam generated external to the accelerating region. The accelerating region may include a superconducting radio frequency (RF) cavity, and the gun may be operated in a continuous wave (CW) mode. The secondary emitter includes hydrogenated diamond. A uniform electrically conductive layer is superposed on the emitter to replenish the extracted current, preventing charging of the emitter. An encapsulated secondary emission enhanced cathode device, useful in a superconducting RF cavity, includes a housing for maintaining vacuum, a cathode, e.g., a photocathode, and the non-contaminating NEA secondary emitter with the uniform electrically conductive layer superposed thereon.

  17. Novel ignition systems for heavy calibre guns

    NASA Astrophysics Data System (ADS)

    Bowden, C. N.; Cook, G. G.; Henning, P. S.

    1986-01-01

    In recent years there was a trend towards steadily rising gun pressures, especially in direct fire weapons and this has caused many functional problems to arise with conventional vent tube ignition systems. To overcome these problems and to allow the process of gun development to continue, the United Kingdom is performing a program of research into a number of ignition systems for heavy caliber guns. These include: spark ignition, laser ignition, and electrical impulse ignition. A number of different spark plug configurations were evaluated. Extensive trials were performed on the ignition characteristics of black powders and black powder substitutes using an experimental 4 J neodymium laser. Work was also performed on the development of high pressure sapphire windows. A study into methods of charge ignition by electrical impulse techniques was also performed.

  18. Improved DC Gun and Insulator Assembly

    SciTech Connect

    Neubauer, Michael; Johnson, Rolland P

    2015-01-11

    Many user facilities such as synchrotron radiation light sources and free electron lasers rely on DC high voltage photoguns with internal field gradients as high as 10 to 15 MV/m. These high gradients often lead to field emission which poses serious problems for the photocathode used to generate the electron beam and the ceramic insulators used to bias the photocathode at high voltage. Ceramic insulators are difficult to manufacture, require long commissioning times, and have poor reliability, in part because energetic electrons bury themselves in the ceramic causing a buildup of charge and eventual puncture, and also because large diameter ceramics are difficult to braze reliably. The lifetimes of photo cathodes inside high current DC guns exhibiting field emission are limited to less than a hundred hours. Reducing the surface gradients on the metals reduces the field emission, which serves to maintain the required ultrahigh vacuum condition. A novel gun design with gradients around 5 MV/m and operating at 350 kV, a major improvement over existing designs, was proposed that allows for the in-situ replacement of photo cathodes in axially symmetric designs using inverted ceramics. In this project, the existing JLAB CEBAF asymmetric gun design with an inverted ceramic support was modeled and the beam dynamics characterized. An improved structure was designed that reduces the surface gradients and improves the beam optics. To minimize the surface gradients, a number of electrostatic gun designs were studied to determine the optimum configuration of the critical electrodes within the gun structure. Coating experiments were carried out to create a charge dissipative coating for cylindrical ceramics. The phase II proposal, which was not granted, included the design and fabrication of an axially symmetric DC Gun with an inverted ceramic that would operate with less than 5 MV/m at 350 kV and would be designed with an in-situ replaceable photo-cathode.

  19. Simulations of Gaussian electron guns for RHIC electron lens

    SciTech Connect

    Pikin, A.

    2014-02-28

    Simulations of two versions of the electron gun for RHIC electron lens are presented. The electron guns have to generate an electron beam with Gaussian radial profile of the electron beam density. To achieve the Gaussian electron emission profile on the cathode we used a combination of the gun electrodes and shaping of the cathode surface. Dependence of electron gun performance parameters on the geometry of electrodes and the margins for electrodes positioning are presented.

  20. Nb-Pb Superconducting RF Gun

    SciTech Connect

    Sekutowicz, J.; Iversen, J.; Kreps, G.; Moller, W.D.; Singer, W.; Singer, X.; Ben-Zvi, I.; Burrill, A.; Smedley, J.; Rao, T.; Ferrario, M.; Kneisel, P.; Langner, J.; Strzyzewski, P.; Lefferts, R.; Lipski, A.; Szalowski, K.; Ko, K.; Xiao, L.; /SLAC

    2006-03-29

    We report on the status of an electron RF-gun made of two superconductors: niobium and lead. The presented design combines the advantages of the RF performance of bulk niobium superconducting cavities and the reasonably high quantum efficiency of lead, as compared to other superconducting metals. The concept, mentioned in a previous paper, follows the attractive approach of all niobium superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead at various photon energies, analysis of recombination time of photon-broken Cooper pairs for lead and niobium, and preliminary cold test results are discussed in this paper.

  1. Nb-Pb superconducting RF gun

    SciTech Connect

    J. Sekutowicz; J. Iversen; G. Kreps; W.D. Moller; W. Singer; X. Singer; I. Ben-Zvi; A. Burrill; J. Smedley; T. Rao; M. Ferrario; P. Kneisel; J. Langner; P. Strzyzewski; R. Lefferts; A. Lipski; K. Szalowski; K. Ko; L. Xiao

    2006-04-14

    We report on the status of an electron RF-gun made of two superconductors: niobium and lead. The presented design combines the advantages of the RF performance of bulk niobium superconducting cavities and the reasonably high quantum efficiency of lead, as compared to other superconducting metals. The concept, mentioned in a previous paper, follows the attractive approach of all niobium superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead at various photon energies, analysis of recombination time of photon-broken Cooper pairs for lead and niobium, and preliminary cold test results are discussed in this paper.

  2. Electron trapping mechanisms in magnetron injection guns

    NASA Astrophysics Data System (ADS)

    Pagonakis, Ioannis Gr.; Piosczyk, Bernhard; Zhang, Jianhua; Illy, Stefan; Rzesnicki, Tomasz; Hogge, Jean-Philippe; Avramidis, Konstantinos; Gantenbein, Gerd; Thumm, Manfred; Jelonnek, John

    2016-02-01

    A key parameter for the gyrotron operation and efficiency is the presence of trapped electrons. Two electron trapping mechanisms can take place in gyrotrons: (i) the adiabatic trap and (ii) the magnetic potential well. Their influence on the gyrotron operation is analyzed. Two gun design criteria are then proposed to suppress both mechanisms in order to minimize the risk of possible problems. Experimental results of three high power gyrotrons are presented and their performance is correlated to the presence of populations of trapped electrons. Finally, some very general gun design principles are presented for the limitation of harmful electron trapping.

  3. Transverse-longitudinal correlations in electron guns

    NASA Astrophysics Data System (ADS)

    Harris, J. R.; Lewellen, J. W.; Poole, B. R.

    2012-07-01

    When a modulated beam is produced in a DC electron gun, the time-dependent space charge force and the time-independent focusing force produce a correlation between current, position along the beam, and the beam's radius and divergence. This has implications for beam extraction and downstream beam transport. Here, we simulate an electrostatically-focused DC electron gun to study this correlation. Beam radius and divergence at the anode are found to be approximately linear functions of beam current, and the consequences for beam loss and extraction are considered.

  4. Dynamics Modelling of Biolistic Gene Guns

    SciTech Connect

    Zhang, M.; Tao, W.; Pianetta, P.A.

    2009-06-04

    The gene transfer process using biolistic gene guns is a highly dynamic process. To achieve good performance, the process needs to be well understood and controlled. Unfortunately, no dynamic model is available in the open literature for analysing and controlling the process. This paper proposes such a model. Relationships of the penetration depth with the helium pressure, the penetration depth with the acceleration distance, and the penetration depth with the micro-carrier radius are presented. Simulations have also been conducted. The results agree well with experimental results in the open literature. The contribution of this paper includes a dynamic model for improving and manipulating performance of the biolistic gene gun.

  5. Do guns provide safety? At what cost?

    PubMed

    Narang, Puneet; Paladugu, Anubha; Manda, Sainath Reddy; Smock, William; Gosnay, Cynthia; Lippmann, Steven

    2010-02-01

    Many people feel that having a gun provides greater safety for them and their family. Actually, having a firearm in the home escalates the risk for death or injury, while using it to shoot someone who endangers the household is much less common. The resultant injuries, deaths, emotional turmoil, and/or disabilities lead to greater utilization of health care and legal/police services. Payment for these expenses is provided by higher insurance premiums and tax rates. This financial aspect has become a part of our country's current political concern over firearm ownership rights, gun violence or regulation, health care costs, the economy, and taxes. PMID:20065902

  6. Gun Injuries More Often Fatal Now, Study Finds

    MedlinePlus

    ... in 2013. Regardless of how people feel about gun control, "there are a number of things we can all agree upon," Sauaia suggested. These include: Children and people who are mentally unstable should not have access to unlocked, loaded guns. Use technology to improve the safety of guns. ...

  7. Aspirator Gun for High-Throughput Mosquito Bioassays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We describe an innovative aspirator gun designed to transfer anaesthetized mosquitoes directly into glass bioassay tubes. The gun has been used for thousands of transfers with extremely low associated mortality and is the central component of a high-throughput bioassay system. The gun is constructed...

  8. Aspirator gun for high-throughput mosquito bioassays.

    PubMed

    Aldridge, Robert L; Wynn, W Wayne; Britch, Seth C; Linthicum, Kenneth J

    2012-03-01

    We describe an innovative aspirator gun designed to transfer individual anesthetized mosquitoes directly into glass bioassay tubes. The gun has been used for thousands of transfers with extremely low associated mortality and is the central component of a high-throughput bioassay system. The gun is constructed using readily obtainable materials and can be modified for a range of insects. PMID:22533090

  9. Youth, Guns, and the Juvenile Justice System. Research Report.

    ERIC Educational Resources Information Center

    Butts, Jeffrey; Coggeshall, Mark; Gouvis, Caterina; Mears, Daniel; Travis, Jeremy; Waul, Michelle; White, Ruth

    This report documents trends in youth gun violence and the response within the justice system, noting the growing variety of data resources available to investigate the effect of new gun laws on youth, communities, and public safety. The first section reviews recent trends, examining the major wave of gun violence in the United States during the…

  10. Product-oriented approaches to reducing youth gun violence.

    PubMed

    Teret, Stephen P; Culross, Patti L

    2002-01-01

    Injury prevention experts have suggested that gun manufacturers could reduce youth violence by changing the design of guns. Product safety features could make guns more difficult for children to fire unintentionally and more difficult to use if stolen or obtained illegally. This article gives a brief history of efforts to make safer, smarter guns and assesses the potential of the product safety approach for reducing youth gun violence. Among the article's key findings: Research from the injury prevention field suggests that changing product design may be more effective in preventing injuries than trying to change personal behaviors; Existing product safety technologies for guns could reduce unintentional gun injuries, especially to young children. In addition, emerging technologies will enable gun manufacturers to "personalize" guns, which could prevent unauthorized users of any age from firing the weapons. Personalization could decrease access to guns by adolescents; Gun manufacturers have been slow to incorporate safety features into their products; but legislative, regulatory, and litigation efforts are under way to mandate safer guns. The authors envision a future when the law requires product safety features--including personalization--on all new firearms. These product safety features have the potential to reduce both intentional and unintentional firearm injury and death. PMID:12194606

  11. Should Gun Safety Be Taught in Schools? Perspectives of Teachers

    ERIC Educational Resources Information Center

    Obeng, Cecilia

    2010-01-01

    Background: Gun-related injuries and deaths among children occur at disproportionately high rates in the United States. Children who live in homes with guns are the most likely victims. This study describes teachers' views on whether gun safety should be taught to children in the preschool and elementary years. Methods: A total of 150 survey…

  12. Gun Violence and Children: Factors Related To Exposure and Trauma.

    ERIC Educational Resources Information Center

    Slovak, Karen

    2002-01-01

    Study investigated relationship between access to firearms and parental monitoring on rural youths' exposure to gun violence, and examined the effect of gun violence exposure on mental health. Results indicated a substantial number were exposed to gun violence. Exposure was related to firearm access and parental monitoring. Implications for social…

  13. VIEW OF SOUTH GUN EMPLACEMENT. NOTE THE EXCAVATED EDGE OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF SOUTH GUN EMPLACEMENT. NOTE THE EXCAVATED EDGE OF THE GUN BLOCK IN THE FOREGROUND. VIEW FACING NORTH - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, South Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

  14. Gun ownership and suicide in the United States.

    PubMed

    Lester, D

    1989-05-01

    The circulation of firearm magazines was used as an index of gun ownership in the states of the USA. States with a higher per capita circulation of firearm magazines had higher suicide rates by gun and higher overall suicide rates. Homicide rates were unrelated to this measure of gun availability. Implications for the prevention of suicide are discussed. PMID:2788293

  15. Geophysical investigation of the pressure field produced by water guns at a pond site in La Crosse, Wisconsin

    USGS Publications Warehouse

    Adams, Ryan F.; Morrow, William S.

    2015-01-01

    The July 2013 study consisted of three scenarios: fish behavior, single gun assessment, and experimental barrier evaluation. The fish behavior scenario simulated the pond conditions from previous studies. Two 80-in3 water guns were fired in the south end of the testing pond. Pressures essentially doubled from the testing of the single 80-in3 water gun. The single gun assessment scenario sought to replicate the setup of the 80-in3 scenario in September 2012, but with additional sensors to better define the pressure field. The 5-lb/in2 target pressure field continued to show a radius ranging from 40 to 45 feet, dependent on the pressure of the input air. The final scenario, the experimental barrier evaluation, showed that a two-dimensional continuous plane of 5 lb/in2 can be created between two 80-in3 water guns to a separation of 99 feet and a depth of 6.5 feet with 1,500 lb/in2 of input air.

  16. [Assessment of noise exposure in sheep].

    PubMed

    Hauser, R; Wechsler, B

    2013-02-01

    The behaviour of sheep was recorded as a reaction to the sound pressure levels caused by shooting with heavy machine guns. The reactions varied in intensity depending on the distance of the source of the noise from the fold. In the case of salvoes that were fired in the immediate vicinity of the fold and were associated with sound pressure levels higher than 120 dB (LCpeak), the sheep reacted with marked fright reactions, and no adaptation to the shooting noise was observed. It is concluded that the tolerable maximum noise level for sheep with this kind of noise source is likely to be less than 120 dB (LCpeak). PMID:23385071

  17. Interior Noise

    NASA Technical Reports Server (NTRS)

    Mixson, John S.; Wilby, John F.

    1991-01-01

    The generation and control of flight vehicle interior noise is discussed. Emphasis is placed on the mechanisms of transmission through airborne and structure-borne paths and the control of cabin noise by path modification. Techniques for identifying the relative contributions of the various source-path combinations are also discussed along with methods for the prediction of aircraft interior noise such as those based on the general modal theory and statistical energy analysis.

  18. Noise Protection

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Environmental Health Systems puts forth an increasing effort in the U.S. to develop ways of controlling noise, particularly in industrial environments due to Federal and State laws, labor union insistence and new findings relative to noise pollution impact on human health. NASA's Apollo guidance control system aided in the development of a noise protection product, SMART. The basis of all SMART products is SMART compound a liquid plastic mixture with exceptional energy/sound absorbing qualities. The basic compound was later refined for noise protection use.

  19. Brontides: natural explosive noises.

    PubMed

    Gold, T; Soter, S

    1979-04-27

    Episodes of explosive noises of natural origin, or brontides, have been well documented, often in association with seismic activity and in a few cases as precursors to major earthquakes. Ground-to-air acoustic transmission from shallow earthquakes can account for many of these episodes, but not for all, and other causes, such as the sudden eruption of gas from high-pressure sources in the ground may at times have been responsible. Confusion with distant thunder or artillery at times of anomalous sound propagation complicates the analysis, and more recently the greatly increased frequency of artificial explosive noises and sonic booms has tended to mask the recognition of natural brontides. PMID:17757998

  20. Is There a Gun in the House? Gun Safety in the Home.

    ERIC Educational Resources Information Center

    Keller, Rosanne

    Written in a conversational style with illustrations, this booklet from a series of home literacy readers is directed at the Alaskan environment where guns are a way of life, used for food and defense from animals. But more than 10% of the 1,300 U.S. deaths from gun accidents occur in Alaska, and more than 70%, at home. Nearly half the victims are…

  1. A Discussion on Personnel Exposure to Posttest Byproducts from a 50-cal. Light Gas Gun

    NASA Technical Reports Server (NTRS)

    Henderson, Don; Rodriquez, Karen

    2007-01-01

    In January of 2002, employees working in the Hypervelocity Test Facility (HTF) at White Sands Test Facility (WSTF) began to notice common physical complaints. These included loss of smell, loss of taste, skin irritation, a burning sensation of the mucus membranes, and redness and chapping of the lips. These conditions extended to home during the weekends and throughout holiday breaks as well. Concerns about air contaminants were raised with regard to the operation of the .50-cal. two-stage light gas gun (2SLGG). Employees suspected that these conditions might be caused by air contaminants from small leaks at the gun pump tube joint at the breech, and exhaust gas entrainment into the WAC systems. The WSTF Industrial Hygienist (IH) was notified and samples were collected using the MIRAN infrared spectrometer (real time) air sampler on 08 January 2002 at the SO-cal. gun. The results from this screening test suggested the need for more detailed investigations with analytical sampling and analysis.

  2. Recreational Gun Use by California Adolescents

    ERIC Educational Resources Information Center

    Vittes, Katherine A.; Sorenson, Susan B.

    2005-01-01

    Most research on adolescents and firearms focuses on urban populations, handguns, and homicide. This study examines the prevalence and correlates of recreational gun use (RGU)--for hunting or target shooting--among 5,801 community-residing 12- to 17-year-old Californians. Data are from the first statewide California Health Interview Survey (CHIS),…

  3. Simulation of an rf thermionic gun

    NASA Astrophysics Data System (ADS)

    Liu, Hongxiu

    1991-07-01

    An rf thermionic gun is simulated using Superfish and Parmela. A strong front-end compression for the bunch is demonstrated. The energy spread, phase spread and emittance of a single electron micropulse are examined subtly by cutting the bunch into slices corresponding to different initial emission phases of the particles.

  4. Gene gun immunization to combat malaria.

    PubMed

    Bergmann-Leitner, Elke S; Leitner, Wolfgang W

    2013-01-01

    DNA immunization by gene gun against a variety of infectious diseases has yielded promising results in animal models. Skin-based DNA vaccination against these diseases is not only an attractive option for the clinic but can aid in the discovery and optimization of vaccine candidates. Vaccination against the protozoan parasite Plasmodium presents unique challenges: (a) most parasite-associated antigens are stage-specific; (b) antibodies capable of neutralizing the parasite during the probing of the mosquitoes have to be available at high titers in order to prevent infection of the liver; (c) immunity to liver-stage infection needs to be absolute in order to prevent subsequent blood-stage parasitemia. Gene gun vaccination has successfully been used to prevent the infection of mice with the rodent malaria strain P. berghei and has been employed in a macaque model of human P. falciparum. DNA plasmid delivery by gene gun offers the opportunity to economically and efficiently test novel malaria vaccine candidates and vaccination strategies, which include the evaluation of novel molecular adjuvant strategies. Here we describe the procedures involved in making and delivering a pre-clinical malaria DNA vaccine by gene gun as well as the correct approach for the in vivo evaluation of the vaccine. Furthermore, we discuss various approaches that either have already been tested or could be employed to improve DNA vaccines against malaria. PMID:23104349

  5. Witness gun for the Argonne Wakefield Accelerator

    SciTech Connect

    Power, J.; Simpson, J.; Chojnacki, E.; Konecny, R.

    1995-06-01

    The witness gun for the Argonne Wakefield Accelerator (AWA) is a six-cell, copper, iris loaded, rf photocathode operating at 1.3 GHz in a {pi}/2 standing wave mode. An intense drive beam (up to 100 nC {at} 20 psec FWHM) used in the AWA project to excite (i.e. drive) wakefields in at least two separate test devices: a dielectric loaded cylindrical waveguide and a plasma cell. In both cases a low charge, low emittance witness beam (0.1 nC charge, 1 {pi}mm-mrad 90% physical emittance) is required to probe (i.e. witness) the wakefields left behind by the drive beam. This paper will primarily discuss the recent progress in the construction of the witness gun, while also briefly summarizing the central design issues of the gun. A brief status report on the dielectric witness gun option is also included. The authors conclude with a short statement on the near term future plans.

  6. Capital Punishment, Gun Ownership, and Homicide.

    ERIC Educational Resources Information Center

    Kleck, Gary

    1979-01-01

    Examines two controversial questions related to the problem of interpersonal violence in America: (1) Does use of the death penalty exert any measurable influence on the rate of homicide in the United States? (2) What relationship, if any, exists between the level of gun ownership and the level of homicide violence? (Author)

  7. College Students Opinions on Gun Violence.

    PubMed

    Lewis, Rhonda K; LoCurto, Jamie; Brown, Kyrah; Stowell, David; Maryman, J'Vonnah; Dean, Amber; McNair, Thoi; Ojeda, Debbie; Siwierka, Julia

    2016-06-01

    Gun violence and control issues have become serious public health problems. This study gathered the opinions from 419 college students from a Midwestern University. Participants were asked about beliefs about purchasing assault weapons, beliefs about bringing handguns to college campuses and beliefs about contributing factors that lead to gun violence. Participants completed surveys online. The findings showed that overall 54 % of respondents believed that military assault weapons should be banned and 53 % agree that teachers should be allowed to carry a registered handgun on campus. There were statistically significant differences between males and females on these issues. For instance, females believed military assault weapons and high capacity magazines should be banned more than 1.9 times (p = .004) p < .05 compared to male students. On the other hand, female students were more likely to believe that school teachers should be allowed to carry registered handguns on school campuses more than 1.55 times (p = .046) p < .05 compared to their male student counterparts. There were no statistically significant differences between ethnic groups. The top four contributing factors that students believed led to gun violence were decline in parenting and family values (17 %), gang involvement (14 %), bullying (13.8 %) and guns being easy to obtain (13.8 %). Limitations and implications for policy work are discussed. PMID:26516018

  8. Performance of photocathode rf gun electron accelerators

    SciTech Connect

    Ben-Zvi, I.

    1993-07-01

    In Photo-Injectors (PI) electron guns, electrons are emitted from a photocathode by a short laser pulse and then accelerated by intense rf fields in a resonant cavity. The best known advantage of this technique is the high peak current with a good emittance (high brightness). This is important for short wavelength Free-Electron Lasers and linear colliders. PIs are in operation in many electron accelerator facilities and a large number of new guns are under construction. Some applications have emerged, providing, for example, very high pulse charges. PIs have been operated over a wide range of frequencies, from 144 to 3000 MHz (a 17 GHz gun is being developed). An exciting new possibility is the development of superconducting PIs. A significant body of experimental and theoretical work exists by now, indicating the criticality of the accelerator elements that follow the gun for the preservation of the PI`s performance as well as possible avenues of improvements in brightness. Considerable research is being done on the laser and photocathode material of the PI, and improvement is expected in this area.

  9. Performance of photocathode rf gun electron accelerators

    SciTech Connect

    Ben-Zvi, I.

    1993-01-01

    In Photo-Injectors (PI) electron guns, electrons are emitted from a photocathode by a short laser pulse and then accelerated by intense rf fields in a resonant cavity. The best known advantage of this technique is the high peak current with a good emittance (high brightness). This is important for short wavelength Free-Electron Lasers and linear colliders. PIs are in operation in many electron accelerator facilities and a large number of new guns are under construction. Some applications have emerged, providing, for example, very high pulse charges. PIs have been operated over a wide range of frequencies, from 144 to 3000 MHz (a 17 GHz gun is being developed). An exciting new possibility is the development of superconducting PIs. A significant body of experimental and theoretical work exists by now, indicating the criticality of the accelerator elements that follow the gun for the preservation of the PI's performance as well as possible avenues of improvements in brightness. Considerable research is being done on the laser and photocathode material of the PI, and improvement is expected in this area.

  10. Toward a terahertz-driven electron gun

    PubMed Central

    Huang, W. Ronny; Nanni, Emilio A.; Ravi, Koustuban; Hong, Kyung-Han; Fallahi, Arya; Wong, Liang Jie; Keathley, Phillip D.; Zapata, Luis E.; Kärtner, Franz X.

    2015-01-01

    Femtosecond electron bunches with keV energies and eV energy spread are needed by condensed matter physicists to resolve state transitions in carbon nanotubes, molecular structures, organic salts, and charge density wave materials. These semirelativistic electron sources are not only of interest for ultrafast electron diffraction, but also for electron energy-loss spectroscopy and as a seed for x-ray FELs. Thus far, the output energy spread (hence pulse duration) of ultrafast electron guns has been limited by the achievable electric field at the surface of the emitter, which is 10 MV/m for DC guns and 200 MV/m for RF guns. A single-cycle THz electron gun provides a unique opportunity to not only achieve GV/m surface electric fields but also with relatively low THz pulse energies, since a single-cycle transform-limited waveform is the most efficient way to achieve intense electric fields. Here, electron bunches of 50 fC from a flat copper photocathode are accelerated from rest to tens of eV by a microjoule THz pulse with peak electric field of 72 MV/m at 1 kHz repetition rate. We show that scaling to the readily-available GV/m THz field regime would translate to monoenergetic electron beams of ~100 keV. PMID:26486697

  11. Protect Children Instead of Guns, 2000.

    ERIC Educational Resources Information Center

    Children's Defense Fund, Washington, DC.

    Noting that firearms outnumber children by a margin of almost three to one in the United States, this report advocates gun safety policies to protect children. The report provides information on trends in youth firearm deaths from 1994 and 1999 and comparisons of U.S. data to those of other industrialized countries. A table delineates 1996-1998…

  12. Common Sense Copper and RF Guns

    SciTech Connect

    Mulhollan, G.

    2005-01-18

    The purpose of this document is to gather together both fundamental information on copper and on the cleaning and operation of copper in RF gun structures. While incomplete, this is a living document and will be added to and updated as necessary.

  13. How Sociology Texts Address Gun Control

    ERIC Educational Resources Information Center

    Tonso, William R.

    2004-01-01

    William R. Tonso has chosen an issue that he knows something about to examine how sociology textbooks address controversy. Appealing for gun control is fashionable, but it is at odds with a fondness that ordinary Americans have for their firearms--one that is supported by a growing body of research on deterrence to crime. There are two sides to…

  14. Protect Children Instead of Guns, 2001.

    ERIC Educational Resources Information Center

    Children's Defense Fund, Washington, DC.

    Noting that firearms outnumber children by a margin of almost three to one in the United States, this report advocates gun safety policies to protect children. The report provides information on trends in youth firearm deaths and finds the statistics alarming, despite recent decline. The first of three tables in the report delineates 1979-1999…

  15. Issue Management and the Australian Gun Debate.

    ERIC Educational Resources Information Center

    Reynolds, Christopher

    1997-01-01

    Examines the rise and fall of media coverage of the issues of gun control and political conflict in Australia after an incident of mass murder in April 1996. Aims to reveal the issue management process that occurred and the hidden agendas that motivated the political and media activity. Demonstrates the media's role in the creation of issue…

  16. Youth Suicide and Guns. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Whether or not a suicide attempt results in death depends in large part on the method chosen. If a teenager attempts suicide with a gun, his or her death is nearly guaranteed. This brief fact sheet presents data on firearms and suicide, the third leading cause of death for adolescents and young adults in the United States. Any number of societal…

  17. Safety Plan for Schools: No Guns

    ERIC Educational Resources Information Center

    Shah, Nirvi

    2013-01-01

    In a pre-emptive move against a school safety proposal from the National Rifle Association that is expected to include a call for more people trained and approved to carry guns at schools, a coalition of civil rights and education groups unveiled its own safety plan last week. It seeks the creation of positive school climates, thoughtful and…

  18. Guns on Campus: A Chilling Effect

    ERIC Educational Resources Information Center

    Mash, Kenneth M.

    2013-01-01

    The author of this article observes that, while much has been written on the overall topic of safety with regard to allowing guns on college campuses, little has been said about how allowing the possession of deadly weapons can create a "chilling effect" on academic discussions. This article considers how some universities have…

  19. RF Gun Photocathode Research at SLAC

    SciTech Connect

    Jongewaard, E.; Akre, R.; Brachmann, A.; Corbett, J.; Gilevich, S.; Grouev, K.; Hering, P.; P.Krejcik,; Lewandowski, J.; Loos, H.; Montagne, T.; Sheppard, J.C.; Stefan, P.; Vlieks, A.; Weathersby, S.; Zhou, F.; /SLAC

    2012-05-16

    LCLS is presently operating with a third copper photocathode in the original rf gun, with a quantum efficiency (QE) of {approx}1 x 10{sup -4} and projected emittance {gamma}{var_epsilon}{sub x,y} = 0.45 {micro}m at 250 pC bunch charge. The spare LCLS gun is installed in the SLAC Accelerator Structure Test Area (ASTA), fully processed to high rf power. As part of a wider photocathode R and D program, a UV laser system and additional gun diagnostics are being installed at ASTA to measure QE, QE lifetime, and electron beam emittance under a variety of operating conditions. The near-term goals are to test and verify the spare photocathode production/installation sequence, including transfer from the final holding chamber to the rf gun. Mid- and longer-term goals include development of a rigorous understanding of plasma and laser-assisted surface conditioning and investigation of new, high-QE photocathode materials. In parallel, an x-ray photoemission spectroscopy station is nearing completion, to analyze Cu photocathode surface chemistry. In this paper we review the status and anticipated operating parameters of ASTA and the spectroscopy test chamber.

  20. Spray Gun With Constant Mixing Ratio

    NASA Technical Reports Server (NTRS)

    Simpson, William G.

    1987-01-01

    Conceptual mechanism mounted in handle of spray gun maintains constant ratio between volumetric flow rates in two channels leading to spray head. With mechanism, possible to keep flow ratio near 1:1 (or another desired ratio) over range of temperatures, orifice or channel sizes, or clogging conditions.

  1. Nerf Guns Strike a Nerve on Campuses

    ERIC Educational Resources Information Center

    Young, Jeffrey R.

    2008-01-01

    Killing zombies on campus just isn't as much fun as it used to be. Students at Bowling Green State University once carried Nerf guns for a week each semester, shooting the zombies before the creatures could tag them. Participants were seen by most bystanders as nerdy but harmless kids who liked role-playing. These days, bright plastic Nerf guns…

  2. Light gas gun with reduced timing jitter

    SciTech Connect

    Laabs, Gary W.; Funk, David J.; Asay, Blaine W.

    1996-12-01

    A gas gun having a prepressurized projectile held in place with a glass rod in compression is described. The glass rod is destroyed with an explosive at a precise time which allows a restraining pin to be moved by pneumatic means and free the projectile.

  3. Toward a terahertz-driven electron gun.

    PubMed

    Huang, W Ronny; Nanni, Emilio A; Ravi, Koustuban; Hong, Kyung-Han; Fallahi, Arya; Wong, Liang Jie; Keathley, Phillip D; Zapata, Luis E; Kärtner, Franz X

    2015-01-01

    Femtosecond electron bunches with keV energies and eV energy spread are needed by condensed matter physicists to resolve state transitions in carbon nanotubes, molecular structures, organic salts, and charge density wave materials. These semirelativistic electron sources are not only of interest for ultrafast electron diffraction, but also for electron energy-loss spectroscopy and as a seed for x-ray FELs. Thus far, the output energy spread (hence pulse duration) of ultrafast electron guns has been limited by the achievable electric field at the surface of the emitter, which is 10 MV/m for DC guns and 200 MV/m for RF guns. A single-cycle THz electron gun provides a unique opportunity to not only achieve GV/m surface electric fields but also with relatively low THz pulse energies, since a single-cycle transform-limited waveform is the most efficient way to achieve intense electric fields. Here, electron bunches of 50 fC from a flat copper photocathode are accelerated from rest to tens of eV by a microjoule THz pulse with peak electric field of 72 MV/m at 1 kHz repetition rate. We show that scaling to the readily-available GV/m THz field regime would translate to monoenergetic electron beams of ~100 keV. PMID:26486697

  4. Collapsible pistons for light-gas guns

    NASA Technical Reports Server (NTRS)

    Teng, R. N.

    1973-01-01

    Moving and expandable parts of gun consist of pump-tube diaphragm, piston, launch-tube diaphragm, and saboted projectile. As a result of improved piston design, pressure cycle has been significantly improved by smoother buildup, increasing muzzle velocities up to 50%.

  5. Acute alcohol consumption, alcohol outlets, and gun suicide.

    PubMed

    Branas, Charles C; Richmond, Therese S; Ten Have, Thomas R; Wiebe, Douglas J

    2011-01-01

    A case-control study of 149 intentionally self-inflicted gun injury cases (including completed gun suicides) and 302 population-based controls was conducted from 2003 to 2006 in a major US city. Two focal independent variables, acute alcohol consumption and alcohol outlet availability, were measured. Conditional logistic regression was adjusted for confounding variables. Gun suicide risk to individuals in areas of high alcohol outlet availability was less than the gun suicide risk they incurred from acute alcohol consumption, especially to excess. This corroborates prior work but also uncovers new information about the relationships between acute alcohol consumption, alcohol outlets, and gun suicide. Study limitations and implications are discussed. PMID:21929327

  6. Design studies for the LCLS 120 Hz RF gun

    SciTech Connect

    Wang, X.J.; Babzien, M.; Ben-Zvi, I.; Chang, X.Y.; Pjerov, S.; Woodle, M.

    2000-11-01

    A preliminary design studies were carried out at Brookhaven National Laboratory for a photocathode RF gun injection system for LCLS 120 Hz operation. The starting point for the design is 50 Hz BNL Gun IV developed by a BNL/KEK/SHI collaboration. The basic parameters of the 120 Hz gun is discussed in this report. The complete photocathode RF gun injection system is described for a 120 Hz operation. The injector system includes photocathode RF gun, emittance compensation solenoid magnet, laser system and laser beam delivery system, and electron beam diagnostics. The basic design parameters, mechanical modification and the performance will be presented in this report.

  7. Acute Alcohol Consumption, Alcohol Outlets, and Gun Suicide

    PubMed Central

    Branas, Charles C.; Richmond, Therese S.; Ten Have, Thomas R.; Wiebe, Douglas J.

    2014-01-01

    A case–control study of 149 intentionally self-inflicted gun injury cases (including completed gun suicides) and 302 population-based controls was conducted from 2003 to 2006 in a major US city. Two focal independent variables, acute alcohol consumption and alcohol outlet availability, were measured. Conditional logistic regression was adjusted for confounding variables. Gun suicide risk to individuals in areas of high alcohol outlet availability was less than the gun suicide risk they incurred from acute alcohol consumption, especially to excess. This corroborates prior work but also uncovers new information about the relationships between acute alcohol consumption, alcohol outlets, and gun suicide. Study limitations and implications are discussed. PMID:21929327

  8. Interpreting the empirical evidence on illegal gun market dynamics.

    PubMed

    Braga, Anthony A; Wintemute, Garen J; Pierce, Glenn L; Cook, Philip J; Ridgeway, Greg

    2012-10-01

    Thousands of Americans are killed by gunfire each year, and hundreds of thousands more are injured or threatened with guns in robberies and assaults. The burden of gun violence in urban areas is particularly high. Critics suggest that the results of firearm trace data and gun trafficking investigation studies cannot be used to understand the illegal supply of guns to criminals and, therefore, that regulatory and enforcement efforts designed to disrupt illegal firearms markets are futile in addressing criminal access to firearms. In this paper, we present new data to address three key arguments used by skeptics to undermine research on illegal gun market dynamics. We find that criminals rely upon a diverse set of illegal diversion pathways to acquire guns, gun traffickers usually divert small numbers of guns, newer guns are diverted through close-to-retail diversions from legal firearms commerce, and that a diverse set of gun trafficking indicators are needed to identify and shut down gun trafficking pathways. PMID:22669643

  9. Gun safety management with patients at risk for suicide.

    PubMed

    Simon, Robert I

    2007-10-01

    Guns in the home are associated with a five-fold increase in suicide. All patients at risk for suicide must be asked if guns are available at home or easily accessible elsewhere, or if they have intent to buy or purchase a gun. Gun safety management requires a collaborative team approach including the clinician, patient, and designated person responsible for removing guns from the home. A call-back to the clinician from the designated person is required confirming that guns have been removed and secured according to plan. The principle of gun safety management applies to outpatients, inpatients, and emergency patients, although its implementation varies according to the clinical setting. PMID:17967118

  10. Gun utopias? Firearm access and ownership in Israel and Switzerland.

    PubMed

    Rosenbaum, Janet E

    2012-02-01

    The 2011 attempted assassination of a US representative renewed the national gun control debate. Gun advocates claim mass-casualty events are mitigated and deterred with three policies: (a) permissive gun laws, (b) widespread gun ownership, (c) and encouragement of armed civilians who can intercept shooters. They cite Switzerland and Israel as exemplars. We evaluate these claims with analysis of International Crime Victimization Survey (ICVS) data and translation of laws and original source material. Swiss and Israeli laws limit firearm ownership and require permit renewal one to four times annually. ICVS analysis finds the United States has more firearms per capita and per household than either country. Switzerland and Israel curtail off-duty soldiers' firearm access to prevent firearm deaths. Suicide among soldiers decreased by 40 per cent after the Israeli army's 2006 reforms. Compared with the United States, Switzerland and Israel have lower gun ownership and stricter gun laws, and their policies discourage personal gun ownership. PMID:22089893

  11. An X-Band Gun Test Area at SLAC

    SciTech Connect

    Limborg-Deprey, C.; Adolphsen, C.; Chu, T.S.; Dunning, M.P.; Jobe, R.K.; Jongewaard, E.N.; Hast, C.; Vlieks, A.E.; Wang, F.; Walz, D.R.; Marsh, R.A.; Anderson, S.G.; Hartemann, F.V.; Houck, T.L.; /LLNL, Livermore

    2012-09-07

    The X-Band Test Area (XTA) is being assembled in the NLCTA tunnel at SLAC to serve as a test facility for new RF guns. The first gun to be tested will be an upgraded version of the 5.6 cell, 200 MV/m peak field X-band gun designed at SLAC in 2003 for the Compton Scattering experiment run in ASTA. This new version includes some features implemented in 2006 on the LCLS gun such as racetrack couplers, increased mode separation and elliptical irises. These upgrades were developed in collaboration with LLNL since the same gun will be used in an injector for a LLNL Gamma-ray Source. Our beamline includes an X-band acceleration section which takes the electron beam up to 100 MeV and an electron beam measurement station. Other X-Band guns such as the UCLA Hybrid gun will be characterized at our facility.

  12. Gun utopias? Firearm access and ownership in Israel and Switzerland

    PubMed Central

    Rosenbaum, Janet

    2011-01-01

    The 2011 attempted assassination of a US representative renewed the national gun control debate. Gun advocates claim that mass-casualty events are mitigated and deterred with three policies: (1) permissive gun laws, (2) widespread gun ownership, (3) encouragement of armed civilians who can intercept shooters, and cite Switzerland and Israel as exemplars. We evaluate these claims with analysis of International Crime Victimization Survey (ICVS) data and translation of laws and original source material. Swiss and Israeli laws limit firearm ownership and require permit renewal 14 times annually. ICVS analysis finds that the US has more firearms per capita and per household than either country. Switzerland and Israel curtail off-duty soldiers firearm access to prevent firearm deaths. Suicide among soldiers decreased by 40% after the Israeli armys 2006 reforms. Compared with the US, Switzerland and Israel have lower gun ownership and stricter gun laws, and their policies discourage personal gun ownership. PMID:22089893

  13. Oxygen partial pressure measurement in the HVOF gun tail flame

    SciTech Connect

    Korpiola, K.; Hirvonen, J.P.; Jalkanen, H.; Laas, L.; Rossi, F.

    1995-12-31

    An important aspect of the HVOF thermal spray process is the turbulent mixing of the spray jet with the surrounding air. The air mixing into the jet causes undesirable oxidation of the sprayed coating. In this paper a low cost and accurate method to determine the degree of air mixing is presented. This method was used to measure for the first time the partial pressure of oxygen in the thermal spray flame. The measuring method is based on electrochemical determination of oxygen potential in the tail flame using a solid electrolyte cell. The oxygen partial pressure in the HVOF-gun tail flame was measured with the fuel-to-oxygen ratio, the fuel flow rate and the stand-off distance as variables. The oxygen content of the tail flame was measured and found to vary between 4 to 17% depending on fuel to oxygen ratios and stand-off distances. Such high oxygen contents are several magnitudes too high if serious oxidation in the coating is to be avoided.

  14. Aircraft and background noise annoyance effects

    NASA Technical Reports Server (NTRS)

    Willshire, K. F.

    1984-01-01

    To investigate annoyance of multiple noise sources, two experiments were conducted. The first experiment, which used 48 subjects, was designed to establish annoyance-noise level functions for three community noise sources presented individually: jet aircraft flyovers, air conditioner, and traffic. The second experiment, which used 216 subjects, investigated the effects of background noise on aircraft annoyance as a function of noise level and spectrum shape; and the differences between overall, aircraft, and background noise annoyance. In both experiments, rated annoyance was the dependent measure. Results indicate that the slope of the linear relationship between annoyance and noise level for traffic is significantly different from that of flyover and air conditioner noise and that further research was justified to determine the influence of the two background noises on overall, aircraft, and background noise annoyance (e.g., experiment two). In experiment two, total noise exposure, signal-to-noise ratio, and background source type were found to have effects on all three types of annoyance. Thus, both signal-to-noise ratio, and the background source must be considered when trying to determine community response to combined noise sources.

  15. Seismic data collection from water gun and industrial background sources in the Chicago Sanitary and Ship Canal area, Illinois, 2011

    USGS Publications Warehouse

    Morrow, William S.; Carpenter, Phillip J.; Adams, Ryan F.

    2015-01-01

    The water gun is a tool adapted from deep marine geophysical surveys that is being evaluated for use as an acoustic fish deterrent to control the movement of invasive marine species. The water gun creates a seismic signal by using a compressed air discharge to move a piston rapidly within the water, resulting in an implosion. This energy pulse may be able to modify fish behavior or destroy marine life, such as the Asian carp, at some distance. The effects of this energy pulse on structures in the Chicago Sanitary and Ship Canal (CSSC), such as canal walls, shore lines, and lock structures, are not known. The potential effects of the use of a water gun on structures was identified as a concern in the CSSC and was assessed relative to existing background sources during this study. During September 2011, two water guns with piston sizes of 80 and 343 cubic inches, respectively, were tested in the CSSC at varying pressures and distances from a canal wall consisting of dolomite and dolomite setblock. Seismic data were collected during these water gun firings using geophones on land, in boreholes, and at the canal wall interface. Data were collected at varying depths in the canal water using hydrophones. Seismic data were also collected during the occurrences of barge traffic, railroad traffic located near the electric fish barrier in Lemont, and coal-loading operations at a coal power plant near the electric fish barrier. In general, energy produced by barge and railroad sources was less than energy created by the water gun. Energy levels produced by coal-loading operations at least 200 feet from geophones were approximately four times lower than energy levels measured during water gun operations.

  16. Helicopter external noise requirements: FAA perspective

    NASA Technical Reports Server (NTRS)

    Foster, C. R.

    1978-01-01

    Enactment of helicopter noise certification standards for the control of noise impact contributing to community annoyance is considered in terms of the development of helicopters as an environmentally compatible air transportation mode. Increased use of helicopters for commercial applications and public awareness of aircraft noise are cited as factors making development of helicopter noise standards necessary both for the protection of the environmental interest of the community and to ensure the orderly growth of the helicopter industry itself. Noise sources, technology trends in helicopter design, and design concepts to control helicopter noise are discussed along with the regulatory background and specific helicopter regulatory concepts.

  17. A high-brightness thermionic microwave electron gun

    SciTech Connect

    Borland, M.

    1991-02-01

    In a collaborative effort by SSRL, AET Associates, and Varian Associates, a high-brightness microwave electron gun using a thermionic cathode has been designed, built, tested, and installed for use with the SSRL 150 MeV linear accelerator. This thesis discusses the physics behind the design and operation of the gun and associated systems, presenting predictions and experimental tests of the gun`s performance. The microwave gun concept is of increasing interest due to its promise of providing higher-current, lower-emittance electron beams than possible from conventional, DC gun technology. In a DC guns, accelerating gradients are less than 8 MV/m, while those in a microwave gun can exceed 100 MV/m, providing much more rapid initial acceleration, thereby reducing the deleterious effects of space-charge. Microwave guns produce higher momentum beams than DC guns, thus lessening space-charge effects during subsequent beam transport. Typical DC guns produce kinetic energies of 80--400 KeV, compared to 2--3 MeV for the SSRL microwave gun. ``State-of-the-art`` microwave gun designs employ laser-driven photocathodes, providing excellent performance but with greater complexity and monetary costs. A thermionic microwave gun with a magnetic bunching system is comparable in cost and complexity to a conventional system, but provides performance that is orders of magnitude better. Simulations of the SSRL microwave gun predict a normalized RMS emittance at the gun exist of < 10 {pi} {center_dot} m{sub e}c {center_dot} {mu}m for a beam consisting of approximately 50% of the particles emitted from the gun, and having a momentum spread {plus_minus}10%. These emittances are for up to 5 {times} 10{sup 9}e{sup {minus}} per bunch. Chromatic aberrations in the transport line between the gun and linear accelerator increase this to typically < 30 {pi} {center_dot} m{sub e} {center_dot} {mu}m.

  18. Noise pollution: a modem plague.

    PubMed

    Goines, Lisa; Hagler, Louis

    2007-03-01

    Noise is defined as unwanted sound. Environmental noise consists of all the unwanted sounds in our communities except that which originates in the workplace. Environmental noise pollution, a form of air pollution, is a threat to health and well-being. It is more severe and widespread than ever before, and it will continue to increase in magnitude and severity because of population growth, urbanization, and the associated growth in the use of increasingly powerful, varied, and highly mobile sources of noise. It will also continue to grow because of sustained growth in highway, rail, and air traffic, which remain major sources of environmental noise. The potential health effects of noise pollution are numerous, pervasive, persistent, and medically and socially significant. Noise produces direct and cumulative adverse effects that impair health and that degrade residential, social, working, and learning environments with corresponding real (economic) and intangible (well-being) losses. It interferes with sleep, concentration, communication, and recreation. The aim of enlightened governmental controls should be to protect citizens from the adverse effects of airborne pollution, including those produced by noise. People have the right to choose the nature of their acoustical environment; it should not be imposed by others. PMID:17396733

  19. Recoil Experiments Using a Compressed Air Cannon

    ERIC Educational Resources Information Center

    Taylor, Brett

    2006-01-01

    Ping-Pong vacuum cannons, potato guns, and compressed air cannons are popular and dramatic demonstrations for lecture and lab. Students enjoy them for the spectacle, but they can also be used effectively to teach physics. Recently we have used a student-built compressed air cannon as a laboratory activity to investigate impulse, conservation of…

  20. Noise Pollution

    MedlinePlus

    ... menu Learn the Issues Air Chemicals and Toxics Climate Change Emergencies Greener Living Health and Safety Land and Cleanup Pesticides Waste Water Science & Technology Air Climate Change Ecosystems Health Land, Waste and Cleanup Pesticides Substances ...

  1. Field Test Kit for Gun Residue Detection

    SciTech Connect

    WALKER, PAMELA K.; RODACY, PHILIP J.

    2002-01-01

    One of the major needs of the law enforcement field is a product that quickly, accurately, and inexpensively identifies whether a person has recently fired a gun--even if the suspect has attempted to wash the traces of gunpowder off. The Field Test Kit for Gunshot Residue Identification based on Sandia National Laboratories technology works with a wide variety of handguns and other weaponry using gunpowder. There are several organic chemicals in small arms propellants such as nitrocellulose, nitroglycerine, dinitrotoluene, and nitrites left behind after the firing of a gun that result from the incomplete combustion of the gunpowder. Sandia has developed a colorimetric shooter identification kit for in situ detection of gunshot residue (GSR) from a suspect. The test kit is the first of its kind and is small, inexpensive, and easily transported by individual law enforcement personnel requiring minimal training for effective use. It will provide immediate information identifying gunshot residue.

  2. Gun muzzle flash detection using a CMOS single photon avalanche diode

    NASA Astrophysics Data System (ADS)

    Merhav, Tomer; Savuskan, Vitali; Nemirovsky, Yael

    2013-10-01

    Si based sensors, in particular CMOS Image sensors, have revolutionized low cost imaging systems but to date have hardly been considered as possible candidates for gun muzzle flash detection, due to performance limitations, and low SNR in the visible spectrum. In this study, a CMOS Single Photon Avalanche Diode (SPAD) module is used to record and sample muzzle flash events in the visible spectrum, from representative weapons, common on the modern battlefield. SPADs possess two crucial properties for muzzle flash imaging - Namely, very high photon detection sensitivity, coupled with a unique ability to convert the optical signal to a digital signal at the source pixel, thus practically eliminating readout noise. This enables high sampling frequencies in the kilohertz range without SNR degradation, in contrast to regular CMOS image sensors. To date, the SPAD has not been utilized for flash detection in an uncontrolled environment, such as gun muzzle flash detection. Gun propellant manufacturers use alkali salts to suppress secondary flashes ignited during the muzzle flash event. Common alkali salts are compounds based on Potassium or Sodium, with spectral emission lines around 769nm and 589nm, respectively. A narrow band filter around the Potassium emission doublet is used in this study to favor the muzzle flash signal over solar radiation. This research will demonstrate the SPAD's ability to accurately sample and reconstruct the temporal behavior of the muzzle flash in the visible wavelength under the specified imaging conditions. The reconstructed signal is clearly distinguishable from background clutter, through exploitation of flash temporal characteristics.

  3. Noise and vibration investigations of the Sandia National Laboratories Sol se Mete Aerial Cable Facility

    SciTech Connect

    Matise, B.K.; Gutman, W.M.; Cunniff, R.A.; Silver, R.J.; Stepp, W.E.

    1994-11-01

    This document is an assessment of the noise, vibration, and overpressure effects and fragmentation hazards of the operation of the Sandia National Laboratories Sol de Mete Aerial Cable Facility (ACF). Major noise sources associated with project operations and considered in this report include rocket motors, chemical explosions, 3-inch gun, 20-mm gun, vehicular traffic, and engines of electricity generators. In addition, construction equipment noise is considered. Noise exposure of ACF personnel is expressed as the equivalent sound level for the 8-hour work day, and is computed by scaling to the proper distance and combining the appropriate noise values for continuously operating equipment such as vehicles and generators. Explosions and gun firings are impulsive events, and overpressures are predicted and expressed as decibel (dB) at the control building, at other nearby facilities, at Sol se Mete. The conclusion reached in the noise analysis is that continuously operating equipment would not produce a serious noise hazard except in the immediate vicinity of the electricity generators and heavy equipment where hearing protection devices should be used. Rocket motors, guns, and detonations of less than 54 kilograms (kg) (120 lb) of explosives would not produce noise levels above the threshold for individual protection at the control building, other nearby test areas, or Sol se Mete Spring. Rare tests involving explosive weights between 54 and 454 kg (120 and 1,000 lb) could produce impulsive noise levels above 140 dB that would require evacuation or other provision for individual hearing protection at the ACF control building and at certain nearby facilities not associated with ACF. Other blast effects including overpressure, ground vibration, and fragmentation produce hazard radii that generally are small than the corresponding noise hazard radius, which is defined as the distance at which the predicted noise level drops to 140 dB.

  4. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 6 2013-10-01 2013-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  5. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 6 2014-10-01 2014-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  6. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 6 2012-10-01 2012-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  7. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  8. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  9. Media violence, gun control, and public policy.

    PubMed

    Zuckerman, D M

    1996-07-01

    Public concern with the national level of violence is discussed, and the complexity of the issue delineated. Research findings in two key areas of the topic, media violence and availability of firearms, are examined, as is their applicability to public policy efforts and recommendations for the prevention of violence. An approach that combines efforts to counteract media violence with those aimed at effective gun control is outlined in terms of bringing about changes in attitudes toward violence and firearm possession. PMID:8827261

  10. An experimental study on microwave electron gun

    SciTech Connect

    Wang, G.; Wu, J.; Wang, Y.

    1995-12-31

    We report both the simulation and experimental results of using a ring cathode instead of the solid cathode to reduce the back bombardment effect of a thermionic cathode microwave electron gun. The result shows that the back bombardment power is decreased about 2/3 without changing the beam quality apparently which allows operation at higher repetition rate. Experimental results are compared with the simulation with good agreement.

  11. Cylinder Fragmentation Using Gas Gun Techniques

    NASA Astrophysics Data System (ADS)

    Thornhill, T. F.; Reinhart, W. D.; Chhabildas, L. C.; Grady, D. E.; Wilson, L. T.

    2002-07-01

    In this study an experimental technique for study of cylinder fracture fragmentation characteristics has been developed on a two-stage light gas gun. This test method allows the study of cylinder fracture fragmentation in a laboratory environment under well-controlled loading conditions. Application of this technique allows measure of failure strain, strain rates, expansion velocity, and fragmentation toughness. Results of several experiments on Aermet steel are presented.

  12. The Development of the Linac Coherent Light Source RF Gun

    SciTech Connect

    Dowell, David H.; Jongewaard, Erik; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling; /SLAC

    2008-09-24

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of

  13. Diagnostics Beamline for the SRF Gun Project

    SciTech Connect

    T. Kamps; V. Durr; K. Goldammer; D. Kramer; P. Kuske; J. Kuszynski; D. Lipka; F. Marhauser; T. Quast; D. Richter; U. Lehnert; P. Michel; J. Teichert; P. Evtushenko; I. Will

    2005-08-22

    A superconducting radio-frequency photo electron injector (SRF gun) is currently under construction by a collaboration of BESSY, DESY, FZR and MBI. The project aims at the design and setup of a CW SRF gun including a diagnostics beamline for the ELBE FEL and to address R&D issues on low emittance injectors for future light sources such as the BESSY FEL. Of critical importance for the injector performance is the control of the electron beam parameters. For this reason a compact diagnostics beamline is under development serving a multitude of operation settings ranging from low-charge (77pC), low-emittance (1 mm mrad) mode to high-charge (2.5nC) operation of the gun. For these operation modes beam dynamics simulations are resulting in boundary conditions for the beam instrumentation. Proven and mature technology is projected wherever possible, for example for current and beam position monitoring. The layout of the beam profile and emittance measurement systems is described. For the bunch length, which varies between 5 ps and 50 ps, two schemes using electro-optical sampling and Cherenkov radiation are detailed. The beam energy and energy spread is measured with a 180-degree spectrometer.

  14. Gas Gun Studies of Interface Wear Effects

    NASA Astrophysics Data System (ADS)

    Jackson, Tyler; Kennedy, Greg; Thadhani, Naresh

    2011-06-01

    The characteristics of interface wear were studied by performing gas gun experiments at velocities up to 1 km/s. The approach involved developing coefficients of constitutive strength models for Al 6061 and OFHC-Cu, then using those to design die geometry for interface wear gas gun experiments. Taylor rod-on-anvil impact experiments were performed to obtain coefficients of the Johnson-Cook constitutive strength model by correlating experimentally obtained deformed states of impacted samples with those predicted using ANSYS AUTODYN hydrocode. Simulations were used with validated strength models to design geometry involving acceleration of Al rods through a copper concentric cylindrical angular extrusion die. Experiments were conducted using 7.62 mm and 80 mm diameter gas guns. Differences in the microstructure of the interface layer and microhardness values illustrate that stress-strain conditions produced during acceleration of Al through the hollow concentric copper die, at velocities less than 800 m/s, result in formation of a layer via solid state alloying due to severe plastic deformation, while higher velocities produce an interface layer consisting of melted and re-solidified aluminum.

  15. Altitude, Gun Ownership, Rural Areas, and Suicide

    PubMed Central

    Kim, Namkug; Mickelson, Jennie B.; Brenner, Barry E.; Haws, Charlotte A.; Yurgelun-Todd, Deborah A.; Renshaw, Perry F.

    2015-01-01

    Objective The authors recently observed a correlation between state altitude and suicide rate in the United States, which could be explained by higher rates of gun ownership and lower population density in the intermountain West. The present study evaluated the relationship between mean county and state altitude in the United States and total age-adjusted suicide rates, firearm-related suicide rates, and non-firearm-related suicide rates. The authors hypothesized that altitude would be significantly associated with suicide rate. Method Elevation data were calculated with an approximate spatial resolution of 0.5 km, using zonal statistics on data sets compiled from the National Geospatial-Intelligence Agency and the National Aeronautics and Space Administration. Suicide and population density data were obtained through the Centers for Disease Control and Prevention (CDC) WONDER database. Gun ownership data were obtained through the CDC’s Behavioral Risk Factor Surveillance System. Results A significant positive correlation was observed between age-adjusted suicide rate and county elevation (r=0.51). Firearm (r=0.41) and non-firearm suicide rates (r=0.32) were also positively correlated with mean county elevation. Conclusions When altitude, gun ownership, and population density are considered as predictor variables for suicide rates on a state basis, altitude appears to be a significant independent risk factor. This association may be related to the effects of metabolic stress associated with mild hypoxia in individuals with mood disorders. PMID:20843869

  16. A Robust High Current Density Electron Gun

    NASA Astrophysics Data System (ADS)

    Mako, F.; Peter, W.; Shiloh, J.; Len, L. K.

    1996-11-01

    Proof-of-principle experiments are proposed to validate a new concept for a robust, high-current density Pierce electron gun (RPG) for use in klystrons and high brightness electron sources for accelerators. This rugged, long-life electron gun avoids the difficulties associated with plasma cathodes, thermionic emitters, and field emission cathodes. The RPG concept employs the emission of secondary electrons in a transmission mode as opposed to the conventional mode of reflection, i.e., electrons exit from the back face of a thin negative electron affinity (NEA) material, and in the same direction as the incident beam. Current amplification through one stage of a NEA material could be over 50 times. The amplification is accomplished in one or more stages consisting of one primary emitter and one or more secondary emitters. The primary emitter is a low current density robust emitter (e.g., thoriated tungsten). The secondary emitters are thin NEA electrodes which emit secondary electrons in the same direction as the incident beam. Specific application is targeted for a klystron gun to be used by SLAC with a cold cathode at 30-40 amps/cm^2 output from the secondary emission stage, a ~2 μs pulse length, and ~200 pulses/second.

  17. Overview of Plasma Guns for PLX

    NASA Astrophysics Data System (ADS)

    Witherspoon, F. Douglas; Bomgardner, Richard; Case, Andrew; Messer, Sarah; Brockington, Samuel; Wu, Linchun; Elton, Raymond; Hsu, Scott; Cassibry, Jason; Gilmore, Mark

    2010-11-01

    Plasma guns are being developed for use on the Plasma Liner Experiment (PLX) located at LANL. The collapsing plasma liner will be formed via merging of 30-60 dense, high Mach number plasma jets (n˜10^16-17 cm-3, M˜10--35, v˜50--70 km/s, rjet˜5 cm) in a spherically convergent geometry. Small parallel-plate railguns are being developed for this purpose. Each gun will operate at ˜300-600 kA peak current, and launch up to ˜8000 μg of high-Z plasma (Ar, Xe) using a ˜50 kJ pfn. We are now successfully operating with very fast gas valve injection of Ar, and have already achieved good performance of 1200 μg at 42 km/s, and 4000 μg at 20-25 km/s at low current. Work is underway to increase both the mass and velocity using higher current. We describe experimental development of the minirailguns and their present and projected performance. We also discuss options for modest size coaxial guns that might achieve the same performance and provide additional control of the plasmoid structure.

  18. Piezoelectric-based energy-harvesting power sources for gun-fired munitions

    NASA Astrophysics Data System (ADS)

    Rastegar, J.; Haarhoff, D.; Pereira, C.; Nguyen, H.-L.

    2006-03-01

    This paper presents a new class of piezoelectric based energy harvesting power sources for use in gun-fired munitions or other similar applications requiring high G survivability . These power sources are designed to harvest energy from the firing acceleration as well as vibratory motion and spinning of munitions during their flight and convert it to electrical energy that could be used directly by power consuming electronics onboard munitions or stored. The power sources are designed to withstand firing accelerations in excess of 100,000 G. The power sources have been shown to have the potential of completely eliminating the need for chemical batteries in many fuzing applications, while having the added advantage of providing for considerably more safety and long shelf life. Prototypes of a number of designs of this class of energy harvesting power sources for various power requirements have been constructed and successfully tested in the laboratory and by the U. S. Army (ARDEC) using air guns.

  19. Design of an electron gun for terahertz radiation source

    NASA Astrophysics Data System (ADS)

    Li, Ji; Pei, Yuan-Ji; Hu, Tong-Ning; Chen, Qu-Shan; Feng, Guang-Yao; Shang, Lei; Li, Cheng-Long

    2014-04-01

    An EC-ITC (External-Cathode Independently Tunable Cells) RF gun was employed with the aim of obtaining short-pulse bunches with high peak current for a terahertz radiation source. A gridded DC gun plays a key role as the external injecting electron source of the ITC RF gun, the performance of which determines the beam quality in the injector and transport line. In order to make the beam well compressed in the ITC RF gun, the energy of the electrons acquired from the gridded DC gun should be 15 keV at most. A proper structure of the gridded gun with double-anode is shown to overcome the strong space- charge force on the cathode, which is able to generate 6 μs beam with 4.5 A current successfully.

  20. Nail Gun Induced Open Head Injury: A Case Report.

    PubMed

    Oh, Hyun Ho; Kim, Young; Park, Sung Choon; Ha, Young Soo; Lee, Kyu Chang

    2014-10-01

    Increasing use of the nail gun has led to higher injury rates from the use of tools with sequential actuation. Nail gun injury can occur to various parts of the body. Very deep penetration in the brain can have fatal results. A 46-year-old male fired shots from a nail gun into his brain in a suicide attempt. This case demonstrated successful surgical management of the resultant open head injury. PMID:27169051

  1. High Peak Power Gyroklystron with an Inverted Magnetron Injection Gun

    NASA Astrophysics Data System (ADS)

    Read, Michael; Neilson, Jeff; Borchard, Philipp; Ives, Lawrence; Lawson, Wes

    2006-01-01

    This paper describes the design of a 25 MW, 30 GHz gyroklystron amplifier based on a coaxial RF structure. The design includes an inverted magnetron injection gun (MIG) for positioning and cooling the inner conductor. The gun produces a very low spread beam that contributes to a device efficiency of 54%. Details are given of the gun, RF structure, input and output couplers and collector.

  2. Progress on using NEA cathodes in an RF gun

    SciTech Connect

    Fliller, R.P., III; Anderson, T.; Edwards, H.; Bluem, H.; Schultheiss, T.; Sinclair, C.; Huening, M.; /DESY

    2005-05-01

    RF guns have proven useful in multiple accelerator applications, and are an attractive electron source for the ILC. Using a NEA GaAs photocathode in such a gun allows for the production of polarized electron beams. However the lifetime of a NEA cathode in this environment is reduced by ion and electron bombardment and residual gas oxidation. We report progress made with studies to produce a RF gun using a NEA GaAs photocathode to produce polarized electron beams. We discuss simulations of ion back bombardment and attempts to reduce the residual gas pressure in the gun are discussed. Future directions are also discussed.

  3. Tearing and MHD Instability During Gun Injection into a Spheromak

    SciTech Connect

    Fowler, T K

    2000-05-11

    Linear stability analysis of a two-cylinder approximation to gun injection--one cylinder to represent the confined spheromak and another to represent the gun--is shown to yield equilibria in which tearing modes exist simultaneously at the magnetic axis and at the geometric (gun) axis, as might be required to sustain helicity injection. These equilibria are MHD stable at the two axes but may have localized MHD instability at an interior minimum in the q profile. The theory predicts two tearing thresholds with successively deeper q minima as the gun current is increased at constant bias flux.

  4. Effects of gun admonitions on the behaviors and attitudes of school-aged boys.

    PubMed

    Hardy, Marjorie S

    2003-10-01

    Gun-safety programs frequently warn children not to touch guns with little consideration that the messages may enhance the allure of the guns. In the current study, boys rated and ranked their preference for a gun in comparison with other desirable objects. One week later, when left alone in the room with the objects, they were forbidden to touch either the gun or some other object. Observations of their behavior and reevaluation of their attitudes followed. Although the boys forbidden to touch the gun did not report an increased preference for it, all participants were significantly more likely to touch the forbidden gun than to touch other forbidden objects. Age, parent- and coach-reported simulated gun-play, and coach-reported risky behavior predicted gun-touching behavior. The results of the current study indicate that guns hold a unique allure and cast further doubt on the ability of gun admonitions to keep children safe around guns. PMID:14578696

  5. 32 CFR 989.32 - Noise.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... database entry. Utilize the current NOISEMAP computer program for air installations and the Assessment... procedures in AFI 32-7063, Air Installation Compatible Use Zone (AICUZ) Program. Draft EIAP aircraft noise/land use analysis associated with air installations will be coordinated with the MAJCOM AICUZ...

  6. 32 CFR 989.32 - Noise.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... database entry. Utilize the current NOISEMAP computer program for air installations and the Assessment... procedures in AFI 32-7063, Air Installation Compatible Use Zone (AICUZ) Program. Draft EIAP aircraft noise/land use analysis associated with air installations will be coordinated with the MAJCOM AICUZ...

  7. Interim prediction method for jet noise

    NASA Technical Reports Server (NTRS)

    Stone, J. R.

    1974-01-01

    A method is provided for predicting jet noise for a wide range of nozzle geometries and operating conditions of interest for aircraft engines. Jet noise theory, data and existing prediction methods was reviewed, and based on this information a interim method of jet noise prediction is proposed. Problem areas are idenified where further research is needed to improve the prediction method. This method predicts only the noise generated by the exhaust jets mixing with the surrounding air and does not include other noises emanating from the engine exhaust, such as combustion and machinery noise generated inside the engine (i.e., core noise). It does, however, include thrust reverser noise. Prediction relations are provided for conical nozzles, plug nozzles, coaxial nozzles and slot nozzles.

  8. Noise: combating a ubiquitous and hazardous pollutant.

    PubMed

    Bronzaft, Arline L.

    2000-01-01

    With a growing body of data suggesting a link between noise and adverse mental and physical health and with noise pollution becoming even more pervasive, especially from the rapid increase in air travel and highway traffic, individuals worldwide are forging alliances to combat this hazardous pollutant. Especially active are the anti-aircraft noise groups. In the United States, the federal government has limited its responsibilities with respect to noise control after an initial interest in the 1970s when legislation was passed promising to protect the American people against the harmful effects of noise. These past years anti-noise activists in the United States have been working arduously to urge the federal government to once again take an active role in abating and controlling noise. They have also been enlisting more citizens to their cause as they educate them to the hazards of noise. PMID:12689475

  9. Low Emittance Guns for the ILC Polarized Electron Beam

    SciTech Connect

    Clendenin, J.E.; Brachmann, A.; Ioakeimidi, K.; Kirby, R.E.; Maruyama, T.; Miller, R.H.; Wang, J.W.; Zhou, F.; /SLAC

    2006-12-01

    Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressed by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of {ge}200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while {ge}500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns.

  10. Low Emittance Guns for the ILC Polarized Electron Beam

    SciTech Connect

    Clendenin, J. E.; Brachmann, A.; Ioakeimidi, K.; Kirby, R. E.; Maruyama, T.; Miller, R. H.; Wang, J. W.; Zhou, F.

    2007-06-13

    Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressed by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of {>=}200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while {>=}500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns.

  11. An Assessment of Commuter Aircraft Noise Impact

    NASA Technical Reports Server (NTRS)

    Fidell, Sanford; Pearsons, Karl S.; Silvati, Laura; Sneddon, Matthew

    1996-01-01

    This report examines several approaches to understanding 'the commuter aircraft noise problem.' The commuter aircraft noise problem in the sense addressed in this report is the belief that some aspect(s) of community response to noise produced by commuter aircraft operations may not be fully assessed by conventional environmental noise metrics and methods. The report offers alternate perspectives and approaches for understanding this issue. The report also develops a set of diagnostic screening questions; describes commuter aircraft noise situations at several airports; and makes recommendations for increasing understanding of the practical consequences of greater heterogeneity in the air transport fleet serving larger airports.

  12. Action Alters Object Identification: Wielding a Gun Increases the Bias to See Guns

    ERIC Educational Resources Information Center

    Witt, Jessica K.; Brockmole, James R.

    2012-01-01

    Stereotypes, expectations, and emotions influence an observer's ability to detect and categorize objects as guns. In light of recent work in action-perception interactions, however, there is another unexplored factor that may be critical: The action choices available to the perceiver. In five experiments, participants determined whether another…

  13. Cyclic Gun--Human Evolution: Soldiers, Guns, Machine Logic, and the Future

    ERIC Educational Resources Information Center

    Blackmore, Tim

    2006-01-01

    Guns, slug-throwing weapons, have evolved as humans have increased their grasp of the mechanical arts. In the near future, however, it seems likely that soldiers' rifles operating at punishing cyclic rates of fire face the limits of physics and materials science--heat and speed will cost accuracy and distance. This article considers not only the…

  14. Testing a GaAs cathode in SRF gun

    SciTech Connect

    Wang, E.; Kewisch, J.; Ben-Zvi, I.; Burrill, A.; Rao, T.; Wu, Q.; Holmes, D.

    2011-03-28

    RF electron guns with a strained superlattice GaAs cathode are expected to generate polarized electron beams of higher brightness and lower emittance than do DC guns, due to their higher field gradient at the cathode's surface and lower cathode temperature. We plan to install a bulk GaAs:Cs in a SRF gun to evaluate the performance of both the gun and the cathode in this environment. The status of this project is: In our 1.3 GHz 1/2 cell SRF gun, the vacuum can be maintained at nearly 10{sup -12} Torr because of cryo-pumping at 2K. With conventional activation of bulk GaAs, we obtained a QE of 10% at 532 nm, with lifetime of more than 3 days in the preparation chamber and have shown that it can survive in transport from the preparation chamber to the gun. The beam line has been assembled and we are exploring the best conditions for baking the cathode under vacuum. We report here the progress of our test of the GaAs cathode in the SRF gun. Future particle accelerators, such as eRHIC and the ILC require high-brightness, high-current polarized electrons. Strained superlattice GaAs:Cs has been shown to be an efficient cathode for producing polarized electrons. Activation of GaAs with Cs,O(F) lowers the electron affinity and makes it energetically possible for all the electrons, excited into the conduction band that drift or diffuse to the emission surface, to escape into the vacuum. Presently, all operating polarized electron sources, such as the CEBAF, are DC guns. In these devices, the excellent ultra-high vacuum extends the lifetime of the cathode. However, the low field gradient on the photocathode's emission surface of the DC guns limits the beam quality. The higher accelerating gradients, possible in the RF guns, generate a far better beam. Until recently, most RF guns operated at room temperature, limiting the vacuum to {approx}10{sup -9} Torr. This destroys the GaAs's NEA surface. The SRF guns combine the excellent vacuum conditions of DC guns and the high

  15. Gun blast - Its propagation and determination

    NASA Astrophysics Data System (ADS)

    Schmidt, E. M.; Kahl, G. D.; Shear, D. D.

    1980-06-01

    Muzzle blast overpressure levels are limiting the operation of high performance gun systems. The pressures at crew stations are of particular concern and have not been well defined either experimentally or analytically. The present paper presents measurement and analysis of the blast fields about a range of weapons from small arms through artillery. The effects of near muzzle flow upon the blast wave are discussed and a scaling relationship is developed from experimental data which is extended to various weapons and shown to predict pressure acceptably.

  16. Electron gun simulation for 95 GHz gyrotron

    SciTech Connect

    Singh, Udaybir; Kumar, Nitin; Sinha, A.K. E-mail: aksinha@ceeri.ernet.in; Purohit, L.P.

    2011-07-01

    A triode type Magnetron Injection Gun (MIG) for a 2 MW, 95 GHz Gyrotron has been designed by using commercially available code EGUN and another in-house developed code MIGANS. The operating mode of the gyrotron is TE{sub 24.8} and it is operated in the fundamental harmonic. The operating voltages of the modulating anode and the accelerating anode are 61 kV and 85 kV respectively. The parametric dependences of modulating anode voltage and cathode magnetic field on the beam quality have also been studied. (author)

  17. Smart gun technology requirements preliminary report

    SciTech Connect

    Weiss, D.R.; Brandt, D.J.; Tweet, K.D.

    1995-05-01

    Goal of the Smart Gun Technology project is to eliminate the capability of an unauthorized user from firing a law enforcement officer`s firearm by implementing user-recognizing-and-authorizing surety technologies. This project is funded by the National Institute of Justice. This document reports the projects first objective: to find and document the requirements for a user-recognizing-and-authorizing firearm technology that law enforcement officers will value. This report details the problem of firearm takeaways in law enforcement, the methodology used to develop the law enforcement officers` requirements, and the requirements themselves.

  18. Characterisation of plasma in a rail gun

    NASA Technical Reports Server (NTRS)

    Ray, P. K.

    1986-01-01

    The mechanism of plasma and projectile acceleration in a DC rail gun is described from a microscopic point of view through the establishment of the Hall field. The plasma conductivity is shown to be a tensor, indicating that there is a small component of current parallel to the direction of acceleration. The plasma characteristics are evaluated in the experiment of Bauer et. al., as a function of plasma mass through a simple fluid mechanical analysis of the plasma. By equating the energy dissipatated in the plasma with the radiation heat loss, the properties of the plasma are determined.

  19. Catalytic Ignitor for Regenerative Propellant Gun

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E. (Inventor); Ferraro, Ned W. (Inventor)

    1997-01-01

    An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the igniter and three alternative mountings thereof within the combustion chamber are disclosed. The ignitor may also be utilized to dispose of contaminated, excess, or waste liquid propellant in a safe, controlled, simple, and reliable manner.

  20. Catalytic ignitor for regenerative propellant gun

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E. (Inventor); Ferraro, Ned W. (Inventor)

    1994-01-01

    An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the ignitor and three alternative mountings thereof within the combustion chamber are disclosed. The ignitor may also be utilized to dispose of contaminated, excess, or waste liquid propellant in a safe, controlled, simple, and reliable manner.

  1. Gas powered fluid gun with recoil mitigation

    DOEpatents

    Grubelich, Mark C.; Yonas, Gerold

    2016-03-01

    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

  2. Gas powered fluid gun with recoil mitigation

    DOEpatents

    Grubelich, Mark C; Yonas, Gerold

    2013-11-12

    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

  3. Gun Possession among American Youth: A Discovery-Based Approach to Understand Gun Violence

    PubMed Central

    Ruggles, Kelly V.; Rajan, Sonali

    2014-01-01

    Objective To apply discovery-based computational methods to nationally representative data from the Centers for Disease Control and Preventions’ Youth Risk Behavior Surveillance System to better understand and visualize the behavioral factors associated with gun possession among adolescent youth. Results Our study uncovered the multidimensional nature of gun possession across nearly five million unique data points over a ten year period (2001–2011). Specifically, we automated odds ratio calculations for 55 risk behaviors to assemble a comprehensive table of associations for every behavior combination. Downstream analyses included the hierarchical clustering of risk behaviors based on their association “fingerprint” to 1) visualize and assess which behaviors frequently co-occur and 2) evaluate which risk behaviors are consistently found to be associated with gun possession. From these analyses, we identified more than 40 behavioral factors, including heroin use, using snuff on school property, having been injured in a fight, and having been a victim of sexual violence, that have and continue to be strongly associated with gun possession. Additionally, we identified six behavioral clusters based on association similarities: 1) physical activity and nutrition; 2) disordered eating, suicide and sexual violence; 3) weapon carrying and physical safety; 4) alcohol, marijuana and cigarette use; 5) drug use on school property and 6) overall drug use. Conclusions Use of computational methodologies identified multiple risk behaviors, beyond more commonly discussed indicators of poor mental health, that are associated with gun possession among youth. Implications for prevention efforts and future interdisciplinary work applying computational methods to behavioral science data are described. PMID:25372864

  4. Gun facilitates adhesive bonding of studs to surfaces

    NASA Technical Reports Server (NTRS)

    Davis, B. K.; Simpson, W. G.

    1969-01-01

    Gun facilitates adhesive bonding of thermoplastic-backed studs to smooth, hard surfaces. Such studs can be used for mounting loads where defacement with drilled holes cannot be tolerated. These studs can be easily removed by softening the plastic bonding with heat from the gun.

  5. Contributions to the velocity spread of magnetron injection guns

    SciTech Connect

    Danly, B.G.; Kimura, T.; Kreischer, K.E.

    1995-12-31

    Various contributions to the velocity spread in magnetron injection guns for gyrotron applications have been studied, including the effects of misalignments, field errors, and cathode surface roughness. The net result of these effects is a substantial increase in spread over the ballistic spread usually calculated with typical gun codes.

  6. Turbulent electron beams generated by magnetron injection guns

    NASA Astrophysics Data System (ADS)

    Kalinin, Yu. A.; Starodubov, A. V.; Mushtakov, A. V.

    2011-06-01

    A detailed experimental investigation of oscillators based on a magnetron injection gun is carried out. Experimental data show that such oscillators offer a considerable advantage over other similar devices; namely, they are capable of generating powerful wideband noiselike microwave oscillations. This is because magnetron injection guns generate turbulent electron beams at their exit.

  7. Gun Access and Safety Practices among Older Adults

    PubMed Central

    Lum, Hillary D.; Flaten, Hanna K.; Betz, Marian E.

    2016-01-01

    Background. Given high rates of gun ownership among older adults, geriatric providers can assess firearm safety practices using a “5 Ls” approach: Locked; Loaded; Little children; feeling Low; and Learned owner. This study describes gun access and the “5 Ls” among US older adults. Methods. Data on the “5 Ls” from the Second Injury Control and Risk Survey (ICARIS-2), a national telephone survey conducted by the Centers for Disease Control and Prevention, were analyzed. Weighted variables were used to generate national estimates regarding prevalence of gun ownership and associated gun safety among older adults (≥55 years). Results. Of 2939 older adults, 39% (95% CI 37%–42%) reported ≥1 gun stored at home. Among those with guns at home, 21% (95% CI 18–24%) stored guns loaded and unlocked; 9.2% (95% CI 6.6–12%) had ≥1 child in household; 5.1% (95% CI 3.5–6.8%) reported past-year suicidal ideation and 3.6% (95% CI 2.1–5.2%) reported history of a suicide attempt; and 55% (95% CI 51–59%) stated that ≥1 adult had attended firearm safety workshop. Conclusion. Some older adults may be at elevated risk of firearm injury because of storage practices, suicidal thoughts, or limited safety training. Future work should assess effective approaches to reduce the risk of gun-related injuries among older adults. PMID:26949391

  8. Carbon-fiber low-voltage electron guns

    SciTech Connect

    Drori, R.; Jerby, E.

    1995-12-31

    Carbon-fiber cathodes am used in cold electron-guns in our laboratory. They operate in low-voltage (< 10 kV) free-electron maser and cyclotron-resonance maser experiments. The paper presents I-V characteristics of various carbon-fiber electron-guns and show results of the corresponding maser experiments.

  9. A theory for coupling gridded gun design with PPM focussing

    NASA Astrophysics Data System (ADS)

    True, R.

    1984-03-01

    It is pointed out that a major fraction of Pierce guns in use today are gridded to allow beam current control and on/off switching by grid voltage levels roughly two orders of magnitude less than the applied cathode-to-anode voltage. Such guns are used in various electron-beam devices, such as microwave and millimeter-wave tubes, linear accelerators, and ubitrons or free electron lasers. It has been customary practice in the design of a gridded gun, to develop first a suitable ungridded or diode gun. In the considered case, difficulties begin to arise after the design of the ungridded gun. In the present paper, a description is given of the theoretical and experimental methods which are useful in the design of gridded guns. Simplified relationships are developed from which the optimum periodic permanent magnetic (PPM) field level for a given gun can be determined in a priori fashion. Attention is given to the concept of tunnel emittance, focussing stability criteria for nonlaminar beams, and the coupling between the gun and PPM focussing problems.

  10. [Dangerousness of blank fright guns and salute rifles].

    PubMed

    Schöning, R; Krause, D; Lichtenberg, W; Schmidt, U; Effenberger, O

    1997-01-01

    According to the German law salute-fire guns altered weapons with a barrel length of more than 60 cm. They have inside the barrel special constructions, which are guiding the gunshot residues under high pressure to the muzzle. Therefore they own an high potential of injury, like blank-cartridge guns with short barrels. PMID:9313063

  11. Self-contained hot-hollow cathode gun source assembly

    DOEpatents

    Zeren, J.D.

    1984-08-01

    A self-contained hot-hollow cathode gun source assembly for use in a vacuum chamber includes a crucible block having a hot-hollow cathode gun mounted underneath and providing a hole for the magnetic deflection of the ion/electron beam into a crucible on top the block.

  12. Self-contained hot-hollow cathode gun source assembly

    DOEpatents

    Zeren, Joseph D.

    1986-01-01

    A self-contained hot-hollow cathode gun source assembly for use in a vacuum chamber includes a crucible block having a hot-hollow cathode gun mounted underneath and providing a hole for the magnetic deflection of the ion/electron beam into a crucible on top the block.

  13. 78 FR 11902 - Review of Gun Safety Technologies

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-20

    ... comments or information are directed to the following Web site: https://www.justnet.org/gun_safety_technology/ . Relevant comments or information may also be emailed to the following address... to help inform its technology assessment and market research of existing and emerging gun...

  14. What we know about gun use among adolescents.

    PubMed

    Wilkinson, D L; Fagan, J

    2001-06-01

    The current generation of American teenagers has grown up surrounded by gun violence. Guns have played a significant role in shaping the developmental trajectories and behaviors of many inner-city youths. In this essay, we examine the role of guns in the lives of young people, and especially in the social and symbolic construction of violent events among adolescents, primarily focusing on males. First, we review studies of gun attitudes and behaviors as well as several epidemiological studies of firearm experiences and risk factors for violence among youth. Second, we summarize several recent studies on the trends in youth violence in relation to firearms. Next, we review findings from our original research based on in-depth interviews with 377 active gun offenders from two socially isolated inner-city neighborhoods. We present descriptive counts for the sample on variables relating to gun acquisition and use. Data on the use of guns in violent events among adolescents are generally lacking in prior research. We attempt to fill that knowledge gap by presenting a summary of our more detailed analysis of gun and nongun use in violent events reported by our respondents. PMID:11771792

  15. A Gridded Electron Gun for a Sheet Beam Klystron

    SciTech Connect

    Read, M.E.; Miram, G.; Ives, R.L.; Ivanov, V.; Krasnykh, A.; /SLAC

    2008-04-25

    This paper describes the development of an electron gun for a sheet beam klystron. Initially intended for accelerator applications, the gun can operate at a higher perveance than one with a cylindrically symmetric beam. Results of 2D and 3D simulations are discussed.

  16. Gun Access and Safety Practices among Older Adults.

    PubMed

    Lum, Hillary D; Flaten, Hanna K; Betz, Marian E

    2016-01-01

    Background. Given high rates of gun ownership among older adults, geriatric providers can assess firearm safety practices using a "5 Ls" approach: Locked; Loaded; Little children; feeling Low; and Learned owner. This study describes gun access and the "5 Ls" among US older adults. Methods. Data on the "5 Ls" from the Second Injury Control and Risk Survey (ICARIS-2), a national telephone survey conducted by the Centers for Disease Control and Prevention, were analyzed. Weighted variables were used to generate national estimates regarding prevalence of gun ownership and associated gun safety among older adults (≥55 years). Results. Of 2939 older adults, 39% (95% CI 37%-42%) reported ≥1 gun stored at home. Among those with guns at home, 21% (95% CI 18-24%) stored guns loaded and unlocked; 9.2% (95% CI 6.6-12%) had ≥1 child in household; 5.1% (95% CI 3.5-6.8%) reported past-year suicidal ideation and 3.6% (95% CI 2.1-5.2%) reported history of a suicide attempt; and 55% (95% CI 51-59%) stated that ≥1 adult had attended firearm safety workshop. Conclusion. Some older adults may be at elevated risk of firearm injury because of storage practices, suicidal thoughts, or limited safety training. Future work should assess effective approaches to reduce the risk of gun-related injuries among older adults. PMID:26949391

  17. Fatal cranial shot by blank cartridge gun: two suicide cases.

    PubMed

    Buyuk, Yalcin; Cagdir, Sadi; Avsar, Abdullah; Duman, Gokce U; Melez, D Oguzhan; Sahin, Feyzi

    2009-08-01

    Blank firing pistols are generally considered to be harmless and these guns are not accepted as being firearms in most countries. Due to lack of legal regulations these guns are easily purchased by anyone aged over 18 years. Reports of serious injuries and even fatalities due to these guns are increasing in the literature. These guns when modified or even unmodified can cause serious and potentially fatal injuries. Without doing any changes to the barrel, using blank or tear gas cartridges, firing at contact range can cause penetration of gas into the body including bone originated from gun powder. We report two suicide cases shooting themselves at temporal region with a blank cartridge gun at contact range. There was no foreign body on radiological examination and there was no trajectory of a bullet inside the brain. In both cases the wound was at the right temporal region and there was defect at temporal bone. There was circular soot around this bone defect. The injury of the brain tissue was localized at the level of the defect but there was widespread subarachnoidal bleeding. We discussed the potential danger of these guns and stressed the need of legal regulations concerning these guns. PMID:19573850

  18. Guns and Crime: Protection versus Peril. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Many Americans, terrified of violent crime, attempt to protect themselves by owning guns. However, statistics provided in this brief fact sheet reveal that people who choose to have a gun easily available are in fact putting their families and friends into greater danger since far more homicides occur during domestic arguments than during…

  19. 10. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), LOOKING AT SOUTHEAST CORNER. BUILDING NO. 332, CHANGE HOUSE, IN RIGHT BACKGROUND; BUILDING NO. 445-F, MAGAZINE, IN LEFT BACKGROUND. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  20. Normative Considerations in the Aftermath of Gun Violence in Schools

    ERIC Educational Resources Information Center

    Gereluk, Dianne T.; Donlevy, J. Kent; Thompson, Merlin B.

    2015-01-01

    Gun violence in American and Canadian schools is an ongoing tragedy that goes substantially beyond its roots in the interlocking emotional and behavioral issues of mental health and bullying. In light of the need for effective policy development, Dianne T. Gereluk, J. Kent Donlevy, and Merlin B. Thompson examine gun violence in schools from…

  1. Taking Aim at Gun Violence: Rebuilding Community Education & Employment Pathways

    ERIC Educational Resources Information Center

    Bryant, Rhonda

    2013-01-01

    In January 2013, President Obama released a plan for protecting children and communities by reducing gun violence. This plan has generated serious debate from both sides of the issue. The ensuing conversations about how to solve the issue of gun violence have been volatile. The President's plan includes reforms to close loopholes on background…

  2. Gun Possession among Massachusetts Batterer Intervention Program Enrollees

    ERIC Educational Resources Information Center

    Rothman, Emily F.; Johnson, Renee M.; Hemenway, David

    2006-01-01

    Batterers with access to firearms present a serious lethal threat to their partners. The purpose of this exploratory study is to estimate the prevalence of and risk markers for gun possession among Massachusetts men enrolled in batterer intervention programs. The authors found that 1.8% of the men reported having a gun in or around their home.…

  3. 15. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), INTERIOR, FOURTH LEVEL. POWDER HOPPER AT TOP OF ELEVATOR SHAFT. POWDER DISTRIBUTED FROM HERE TO LOADING ROOMS BY TUBES. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  4. Guns and Fear: A One-Way Street?

    ERIC Educational Resources Information Center

    Hauser, Will; Kleck, Gary

    2013-01-01

    Surveys show that more than one half of gun owners report owning their firearm for self-protection. Although research has examined the effect of fear of crime on gun ownership, the issue of reciprocity and temporal order has been largely ignored. Furthermore, the effect of firearm acquisition and relinquishment on fear has not been evaluated…

  5. 10. Detail of map showing Battery Davis and Panama Gun ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Detail of map showing Battery Davis and Panama Gun Mounts at right, by U.S. Engineering Office, San Francisco, California, August 5, 1934. - Fort Funston, Panama Mounts for 155mm Guns, Skyline Boulevard & Great Highway, San Francisco, San Francisco County, CA

  6. NASCAP simulation of laboratory charging tests using multiple electron guns

    NASA Technical Reports Server (NTRS)

    Mandell, M. J.; Katz, I.; Parks, D. E.

    1981-01-01

    NASCAP calculations have been performed simulating exposure of a spacecraft-like model to multiple electron guns. The results agree well with experiment. It is found that magnetic field effects are fairly small, but substantial differential charging can result from electron gun placement. Conditions for surface flashover are readily achieved.

  7. 62. SIXTEEN INCH GUN MOUNTED ON THE MACHINING LATHE; LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. SIXTEEN INCH GUN MOUNTED ON THE MACHINING LATHE; LOOKING WSW. THE GUN ITSELF EXTENDS BEYOND THE BRICK ARCHES OF THE MAIN SHOP FLOOR'S W WALL AND INTO THE W AISLE. THE LATHE'S CUTTING HEAD CAN BE SEEN AT THE RIGHT CENTER OF THE VIEW. (Ryan) - Watervliet Arsenal, Building No. 110, Hagner Road between Schull & Whittemore Roads, Watervliet, Albany County, NY

  8. 16. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), INTERIOR, SECOND LEVEL. LOOKING UP AT POWDER AND DISTRIBUTION TUBES. ELEVATOR SHAFT ON LEFT. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  9. Fluidized bed combustor and coal gun-tube assembly therefor

    DOEpatents

    Hosek, William S.; Garruto, Edward J.

    1984-01-01

    A coal supply gun assembly for a fluidized bed combustor which includes heat exchange elements extending above the bed's distributor plate assembly and in which the gun's nozzles are disposed relative to the heat exchange elements to only discharge granular coal material between adjacent heat exchange elements and in a path which is substantially equidistant from adjacent heat exchange elements.

  10. View forward of five inch gun mounted in sponson; note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View forward of five inch gun mounted in sponson; note glass windows which would be removed in combat, gudgeons below window allowed attachment of armor plate which could be swung up to protect gun crew in battle; also note lower section of flag rack at top left center of photograph. (p39) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  11. VIEW OF EAST GUN EMPLACEMENT. NOTE THE STEEL REINFORCING RODS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF EAST GUN EMPLACEMENT. NOTE THE STEEL REINFORCING RODS PROTRUDING FROM THE BROKEN TOP OF THE RETAINING WALL. VIEW FACING NORTHEAST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, East Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

  12. 83. GENERAL VIEW FROM NORTH END OF GUN HILL PLATFORM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    83. GENERAL VIEW FROM NORTH END OF GUN HILL PLATFORM OF 3RD AVENUE EL SHOWING THE SOUTHBOUND TRACK APPROACH INTO GUN HILL STATION. 7TH AVENUE EXPRESS EL ABOVE. - Interborough Rapid Transit Company, Third Avenue Elevated Line, Borough of the Bronx, New York County, NY

  13. VIEW OF GUN EMPLACEMENT AND THE TABLELIKE CAST CONCRETE STRUCTURE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF GUN EMPLACEMENT AND THE TABLE-LIKE CAST CONCRETE STRUCTURE SHOWING THE SPALLED AREA ON ITS EAST SIDE (LEFT) WHERE THE SECOND PROJECTING ARM WAS BROKEN OFF. NOTE THE SLOPED CONCRETE PAD IN THE BACKGROUND. VIEW FACING SOUTHWEST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, East Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

  14. Everyday Engineering: What Makes a Squirt Gun Squirt?

    ERIC Educational Resources Information Center

    Moyer, Richard; Everett, Susan

    2009-01-01

    You may not think of engineering and squirt guns in the same sentence. However, like many examples of engineering design, the squirt gun pump mechanism is uncomplicated, yet elegant, and very inexpensive to manufacture. The design is widely used because of its simplicity and low cost. With only a few moving parts, it is able to deliver a stream of…

  15. Preventing Clogging In A Vacuum Plasma Spray Gun

    NASA Technical Reports Server (NTRS)

    Krotz, Phillip D.; Daniel, Ronald L., Jr.; Davis, William M.

    1994-01-01

    Modification of powder-injection ports enables lengthy, high-temperature deposition operations. Graphite inserts prevent clogging of ports through which copper powder injected into vacuum plasma spray (VPS) gun. Graphite liners eliminate need to spend production time refurbishing VPS gun, reducing cost of production and increasing productivity. Concept also applied to other material systems used for net-shape fabrication via VPS.

  16. Plans: Aft Gun Platform, Quarters for 16 Gunmen, Poop Deck, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Plans: Aft Gun Platform, Quarters for 16 Gunmen, Poop Deck, Boat Deck, House Top, Bridge Deck, Upper Bridge Deck, Navigating Bridge, Forecastle Deck, Gun Platform, Upper Deck, Second Deck and Hold Plan - Mission Santa Ynez, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  17. Teaching Safety Skills to Children to Prevent Gun Play

    ERIC Educational Resources Information Center

    Himle, Michael B.; Miltenberger, Raymond G.; Flessner, Christopher; Gatheridge, Brian

    2004-01-01

    Research has shown that children often engage in gun play when they find a firearm and that this behavior is often involved in unintentional firearm injuries. Previous research has shown existing programs to be ineffective for teaching children safety skills to reduce gun play. This study examined the effectiveness of a behavioral skills training…

  18. Guns, Mental Illness, and the Law: Introduction to This Issue.

    PubMed

    Swanson, Jeffrey W; Felthous, Alan R

    2015-06-01

    Firearm violence is a top-tier public health problem in the U.S., killing 33,563 and injuring an additional 81,396 people in 2012 (Centers for Disease Control and Prevention, CDC, ). Given constitutional protection and the cultural entrenchment of private gun ownership in the U.S., it is likely that guns will remain widely accessible--and largely unrestricted--for the foreseeable future. Therefore, most policies and laws intended to reduce firearm violence focus selectively on preventing "dangerous people" from having access to guns. That is a formidable challenge. How do we think productively about guns and mental illness in this context, and about the role of law in lessening the toll of gun violence? PMID:25874748

  19. Cure violence: a public health model to reduce gun violence.

    PubMed

    Butts, Jeffrey A; Roman, Caterina Gouvis; Bostwick, Lindsay; Porter, Jeremy R

    2015-03-18

    Scholars and practitioners alike in recent years have suggested that real and lasting progress in the fight against gun violence requires changing the social norms and attitudes that perpetuate violence and the use of guns. The Cure Violence model is a public health approach to gun violence reduction that seeks to change individual and community attitudes and norms about gun violence. It considers gun violence to be analogous to a communicable disease that passes from person to person when left untreated. Cure Violence operates independently of, while hopefully not undermining, law enforcement. In this article, we describe the theoretical basis for the program, review existing program evaluations, identify several challenges facing evaluators, and offer directions for future research. PMID:25581151

  20. ONEGUN: an interior ballistics code for closed breech guns

    SciTech Connect

    Reis, G.E.

    1982-07-01

    This program computes the gun and projectile motion and the gas thermodynamic properties (the internal ballistics) of a closed breech gun. Heat losses and friction losses are taken into account. A dual grain charge can be used. The inputs required are the usual propellant characteristics (density, impetus, gamma, burn rate coefficient and exponent, grain geometry, covolume and isochoric flame temperature). The gun characteristics (chamber volume and length, rifle twist rate, bore diameter, gun weight and start pressure) and the projectile characteristics (projectile weight, radius of gyration and start pressure). The output consists of the motion (displacement, velocity, and acceleration) of both the projectile and the recoiling gun and the gas pressures and temperature, all as a function of time.